I am pleased to make available a free chart depicting the minimum quantities required of matzah and of maror, from a rationalist perspective. You can download it at this link. Share and enjoy!
(For details about the reasoning behind this chart, see http://www.rationalistjudaism.com/2017/03/the-kezayis-post.html.)
Monday, April 2, 2012
106 comments:
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My, this is interesting. Rav Chaim Kanievsky ztz"l was proclaimed for many years to be the authoritative voice of Daas Torah . Countle...
Cute.
ReplyDeletelol
Are we to understand from your chart that pimentos are not kosher l'Pesach?
lol :)
ReplyDeleteIt's more than length, though, it's also depth. So that olive size needs to be equal the amount of matza crushed up to equal that size. How big would that be?
ReplyDeleteIf you crush it up and compress it, you could probably get several Matzot into the volume of a Zayit.
DeleteBut, seriously, a great Rav I know suggested shellacking a Matzah and finding out how much of it displaces as much water as an olive. I believe that in that manner you reach about the same amount of Matzah as Rav Slifkin has suggested (about a credit card sized piece of Matzah)
My wife wants to know if the olive used for determination is a Suri/Nabali (the Egori)
ReplyDeleteBrilliant! My roommate is staring oddly due to my sudden uncontrollable laughter.
ReplyDeleteDo you mean this in actuality? Would you count an actual olive (as pictured) volume sufficient for matzah and marror?
Hilarious!
ReplyDeleteNicely done.
That's terrfic! Thanks for the laugh.
ReplyDeleteI love it!!!
ReplyDeleteAh, what about jumbo olives?
ReplyDeleteAnd what about jumbo Matzot? ;-)
DeleteAbsolutely hilarious!
ReplyDeleteSorry the zayis is measured with its pit. The one pictured is misleading.
ReplyDeleteNice! It should be noted that there are many who have written on the kezayis issue who fully recognise both that our olives have not changed in size since the time of Chazal and that the reason the shiur 'grew' is because the Ashkenazi rishonim didn't have olives, yet still advocate that we eat larger shiurim, at least lechatchila. See the following:
ReplyDeletehttp://www.hebrewbooks.org/pdfpager.aspx?req=13108&st=&pgnum=111
http://hebrewbooks.org/pdfpager.aspx?req=49153&st=&pgnum=22&hilite=
Not so impressed - simple mockery of what really is a useful tool. You could have made a real chart showing what an actual k'zayis of matzah according to your opinion would be. (In case it needs to be spelled out - obviously, matzah is not as think as an olive. You should have calculated the actual volume of an average olive, calculated the average thickness of a piece of matzah, and made a chart showing the area that would be needed in order for the volume of matzah (based on its average thickness) to equal the volume of the average olive.
ReplyDeleteGreat and to the point.
ReplyDeleteLawrence Kaplan
I think you should check to make sure that your chart prints out WYSIWYG (k'lo'mar: the right size when printed out.) Otherwise it may cause people to eat unnecessarily large amounts of matzah/maror.
ReplyDeleteThat is one huge olive! Oh, wait, I think I've got my screen set to an increased zoom size.
ReplyDeleteHilarious! I'll be at the Sedarim with someone who has a nice laminated chart with boxes of various sizes indicating the amount of matzah, etc. needed to make up a kezayis. I can't wait to show off my own new chart!
ReplyDelete'Tis the season when bochurim come home from their Israeli yeshivot, and I heard someone mention that they invariably end up eating enormous "kezeisim" at their Sedarim. I find this very ironic because, as a commenter on another post pointed out, we're losing the forest for the trees. Chazal, who were living in Israel, needed a minimum Shi'ur for what is considered eating (as opposed to nibbling, tasting, or what have you). Because olives abounded, and olives are small fruits that are certainly considered to be "eaten" when consumed, they chose the size of an olive for their Shi'ur. As R' Slifkin explains in his essay, this size became confused over the years when Ashkenazi authorities didn't have olives available. Now our bochurim are coming back from Israel, where they could see first-hand the type of olives that Chazal based their measurements on, and are ignoring this.
What we need is a Revolution of the Olive that will counteract its evolution.
I SO saw that coming.
ReplyDeleteactally, a kzayis is the volume of a whole olive, including the pit. your chart seems to say that one only needs to eat the volume of the edible part of the olive.
ReplyDeleteThis is amazing
ReplyDeleteThis is the same chart my grandfather used...
Not very useful. In all seriousness, I would like a matzah/maror chart for rationalists.
ReplyDeleteThis is SATIRE. Some of you need to lighten up.
ReplyDelete"This is SATIRE. Some of you need to lighten up."
ReplyDeleteThis is the standard defense of leitzanus. Purim is over.
I'm not sure if the people who demand "rationalist" charts with measurements are serious or not... Maybe you should start selling plastic olives.
ReplyDeleteAnyway, on this topic:
http://www.youtube.com/watch?v=9WG14-qybok&feature=youtu.be
Do you mean this in actuality? Would you count an actual olive (as pictured) volume sufficient for matzah and marror?
ReplyDeleteWhy not?
Sorry the zayis is measured with its pit. The one pictured is misleading.
ReplyDeleteDo you know how hard it is to find a picture of a single olive on the Internet?
But in any case, the missing pit does not change the volume!
You should have calculated the actual volume of an average olive, calculated the average thickness of a piece of matzah, and made a chart showing the area that would be needed in order for the volume of matzah (based on its average thickness) to equal the volume of the average olive.
ReplyDeleteNo! Aside from the point about the size of the olive, the other point is that the whole idea of doing what you say is untraditional and hence unnecessary.
Do not follow your response. The commenter has a valid point that the volume of matza should equal the volume of an olive, why do you disagree? Please elaborate.
Delete"This is SATIRE."
ReplyDelete>This is the standard defense of leitzanus.
It's not satire and it's not leitzanus. It's making a serious point in an amusing way.
This is the same chart my grandfather used...
ReplyDeleteI made a one-time exception for anonymous comments, since that comment so perfectly encapsulates the point.
Is a fresh olive a different size than the pickled or cured one shown in the picture?
ReplyDelete"It's not satire and it's not leitzanus. It's making a serious point in an amusing way."
ReplyDeleteNo it is making a serious point by making light of the opinion of poskim you disagree with.
Would you like to elaborate?
ReplyDeleteHow does making a humorous depiction of my OWN view (and that of various authorities) equal leitzanus?
ReplyDeleteYou view is only depicted in a humorous manner because of the implicit reference to the charts made to demonstrate the views of those you disagree with.
ReplyDeleteYes. And how exactly is it leitzanus?
ReplyDeleteI don't disagree!
ReplyDeleteI saw another chart going around Facebook.
ReplyDeleteMatzah Guide
I think it's a bit more practical.
Why is it when our Gedolim give their view on the animal kingdom you sometimes discredit it, as in your view they did not study zoology sufficiently to give a correct opinion, but when it comes to matter of Halacha, where others who have spent their life delving into Gemorrah, Rishonim, Achronim and with all due respect many more years than you, you think its ok to argue with them.
ReplyDeleteTry being a bit more consistant...,
Volume is not density, so the pit is not relevant.
ReplyDeleteI wish you had a different picture, though. If I needed to eat a minimum shiur (due to illness), rather than just eating like a normal human being as the Torah and Chazal clearly intended, I would probably use a fully-grown black olive as my reference.
To those feigning some kind of righteous outrage: deep down you know Rabbi Slifkin is right and a host of others you admire are wrong and that is why it bothers you so much.
ReplyDeleteWhy is it when our Gedolim give their view on the animal kingdom you sometimes discredit it, as in your view they did not study zoology sufficiently to give a correct opinion, but when it comes to matter of Halacha, where others who have spent their life delving into Gemorrah, Rishonim, Achronim and with all due respect many more years than you, you think its ok to argue with them.
ReplyDeleteIt has very little to do with how much zoology they have/ have not learned and nothing to do with discrediting. It has to do with epistemology and worldview.
Obama has spent many more years studying politics than you. Practitioners of eastern medicine have spent many more years studying it than you. The Pope has spent many more years studying the Bible than you. Why do you think it's okay to disagree with all these people? Answer - because you're starting with a fundamentally different set of assumptions. So too here.
it has to be an average olive.
ReplyDeleteI hope that Jews of reason will open the door to Pesach being a holiday of joy and freedom. Halakha can and must be rationally based. Kol hakavod to Rabbi Slifkin for raising awareness on this issue.And kol hakavod to Rabbi David Bar-Hayim for his activity and p'sak halakha on this issue as well.
ReplyDeleteR' Slifkin: Just to clarify, you are saying that a two-dimensional (flat) piece of matza this size is enough? No need for stacking or certainly crushing to fit the volume of an olive as well?
ReplyDeleteNo, of course it has to be the volume of an olive!
ReplyDelete(But stacked, not crushed)
ReplyDelete"No! Aside from the point about the size of the olive, the other point is that the whole idea of doing what you say is untraditional and hence unnecessary."
ReplyDeleteI never said it was either traditional or necessary. What was probably traditional is that nobody really knew exactly how much area of a matzah is enough, so they ate until they were satisfied that they certainly ate enough. The purpose of a chart that I proposed (as Amateur showed that someone has actually produced) is to help people who can't do what is traditional and want to know what the actual minimum size is. What's so wrong or "nonrationalist" about that?
"That's the chart my grandfather used!" Yes, well your grandfather also believed the mabul really happened, that sheishes y'mei b'reishis really happened etc. If you consider yourself more sophisticated than he was regarding hashkafos why can't you also be regarding shiurim?!
ReplyDeleteBecause it would be sophistry, not sophistication.
ReplyDeleteTo clarify a point that R' Natan made. I see no basis for a requirement to measure the minimum volume of matzah eating by crushing a matzah and measuring the volume of the particles. The normal void spaces within a matzah are part of the product and should be counted. For example, does anyone believe that the shiur of a beitza of sponge cake for an 'Al Hamichya' beracha or Sukkah requirement is determined by compressing the cake? Instead, as R' Natan suggested, simple stacking of pieces of matzah should suffice provided that one discounts the spaces between the matzah pieces. As a mere suggestion and a kind of stringency, I would consider half the volume to be empty space and would then take twice the volume of the olive pictured (in 3D, of course) to be a minimum shiur. Perhaps I should not be so quick with my opinions on practical shiurim since I don't have any rabbinic credentials. However, the current yeshivish fad to use greatly exaggerated shiurim is very aggravating and requires opposition to prevent it from becoming the new norm. That being said, there is no virtue in making a fuss at the sedarim about such matters once one has demonstrated what a realistic minimum shiur should be.
ReplyDeletecan someone help me out here? R' Slifkin what about the gemara in arbei p'sachim that talks about the measuring cup used in the town for figuring out the size of the revi'is?
ReplyDeleteRabbi Slifkin is right.
ReplyDeleteHow many of you pullout your pocket rulers at a kiddush to measure the crackers served to make sure you have a Kzayit? I think the "K" in front of "zayit" comes to tell us the same lesson as the "K" in front of "chatzi Halaila". Anyway, getting back to the point, if your going to look back to the time when our Bubbes and Zaydes knew what an olive was, then you should recognize that they also went with their instinct and did nto pull a micormeter from their pocket to measure the thickness of their matza before Pesach.
However, for those who like to know numbers, I have worked up this machmir math for you. Please adapt to fit your Matzot.
6cc = 0.4 US Tablespoons
1 US Tablespoon of Matza Meal (no air) has 8.6 grams of carbs.
0.4 US Tablespoons = 3.44g carbs
Matza has a carb factor of 0.75 meaning that 75% of its weight is carbohydrates.
3.44g / 75% = 4.6g of Matza per K'zayit
Where I live, Matza comes in 1lb boxes or 454g. There are usually about 10 matzot in machine made Shmurah matza. That's 45g/Matza, so you will be yotzei with just over 1/10 of the Matza.
Hand made Matzot are about 8 to a 454g boxes, so each one weighs about 57g. About 1/12 of that Matza will do.
Of course you should check the number of Matzot per box and the weight of your box before relying on these measurements - which is exactly why going this route, of defined measurements, is so problematic.
Source for Matza facts: http://star-k.org/kashrus/kk-passover-diabetics.htm
Slightly off topic- The case for eating two K'zaytim for Motzei Matza has always confused me. Anyone who can explain where the idea of eating two came from and if it's required, a chumra, or just minhag would be appreciated. Of course now that I know what K'zayit is, it doesn't make much of a difference for me. I can eat 1/5 of a Matza without a problem.
As an amendment to my previous post, I would like to add this revised calculation that doesn't rely on the carb percent which can vary by producer. Here's an alternate calculation based on data from a can of Yehuda Matza Meal.
ReplyDelete[ From: http://caloriecount.about.com/calories-yehuda-matzos-jerusalem-matzo-meal-i185219 ]
0.25 US cups Matza meal = 30.3g
0.25 US cups = 59.15cc
59.15cc = 30.3g
6cc = 3.1g
So, my calculated k'zayit just shrunk. I leave it as an exercise to the reader to figure out what part of their Matza that amounts to.
The only thing I would keep in mind, is this - If all year long you tell yourself that you need to eat X number of crackers before making a Bracha Achrona and that same number of crackers would be more than the amount of Matza my calculations show, - I would be consistent with what I do all year long. (Which is how I always felt, and found greatly disturbing that at Pesach time, in yeshiva, I was taught you needed to eat like 4x what would normally be a K'zayit the rest of the year. Didn't make any sense. As a rationalist today, I feel better intellectually, I no longer feel like my head is going to explode, and this year, Friday night, I won't feel like my gut is going to explode either.)
R' Slifkin, can you please address the gemara in arbei p'sachim?
ReplyDeleteNOW I"M REALLY SCREWED
ReplyDeleteI HAD MY MONITOR ON HIGH HIGH RESOLUTION
THIS THING PRINTS OUT THE SIZE OF AN APPLE
THANKS A LOT SLIFKIN!!!!!!
"
ReplyDeleteThe only thing I would keep in mind, is this - If all year long you tell yourself that you need to eat X number of crackers before making a Bracha Achrona and that same number of crackers would be more than the amount of Matza my calculations show, - I would be consistent with what I do all year long. (Which is how I always felt, and found greatly disturbing that at Pesach time, in yeshiva, I was taught you needed to eat like 4x what would normally be a K'zayit the rest of the year. Didn't make any sense. As a rationalist today, I feel better intellectually, I no longer feel like my head is going to explode, and this year, Friday night, I won't feel like my gut is going to explode either.)"
Bear in mind that eating Matzah is a Deoreita Mitzvah, and eating crackers for Kiddush is D'rabanan. So your Kzayit for Matzah SHOULD be larger than your Kzayit for Kiddush. On the other hand, your Kzayit for Yom Kippur, should be SMALLER than your kzayit for Kiddush, and maybe even your kzayit for Matzah. (Assuming that you truly do not understand how much food is a kzayit... You know, like people who hate olives and never eat them or buy them or see them.)
On the one hand, you think that modern scientific understanding should not affect prior psak (as in the case of the worms in fish, where you are adamant that we should follow the Dor Revii's view and ignore the established scientific reality of the lifecycle of anisakis); on the other hand, you think that your modern view of the kazayis (which is inextricably predicated on an historical-positivist view of the development of halacha including inferences about which medieval poskim had access to olives) should affect psak.
ReplyDeleteSo how much do you actually eat?
I explained the difference in the essay.
ReplyDeleteLOL. I printed up your chart, and I used two lines of the empty space to fill in Professor Menachem Kellner's core beliefs. What do I with the rest of the paper?
ReplyDeleteYour explanation in the essay was not philosophical. The question is, if not for your modern empirical mindset, you would never have considered the evidence that you have, nor would you have reinterpreted the Rambam and others to mean an average actual size instead of an upper bound. If you took the pre-empirical mindset of most poskim (until recently), you would not have reached the same conclusions. Just like in the case of the anisakis, without a positivist mindset, current poskim would not have questioned the status of fish. You are trying to have it both ways -- use empiricism when it gets the desired result, ignore it when it does not. It's not enough to point to manuscripts of the Gaonim, or possible interpretations of the Rambam -- you have to establish why you think employing an empirical approach to change long-standing halacha is acceptable philosophically? You've already argued the opposite quite convincingly in the anisakis case.
ReplyDeleteIf you took the pre-empirical mindset of most poskim (until recently), you would not have reached the same conclusions.
ReplyDeleteBut R. Chaim of Volozhin, the Avnei Nezer, and Akiva Yosef Schlesinger reached these conclusions.
Please don't avoid the philosophical dissonance between your two positions -- just address it directly.
ReplyDeleteAs for your 3 poskim who are exceptions -- that's what exceptions are -- they prove the rule. But the two main poskim and codifiers of the past century, the Mishneh Berurah and the Aruch HaShulchan, did not accept this approach. Nor did any of the major poskim of the last generation. So citing exceptions with idiosyncratic views really strengthens the argument against your position.
R' Slifkin, why I am I being ignored? There is an important gemara in arbei p'sachim that sounds like they used a measuring cup to determine the size of the revi'is. I assume there is no difference between a revi'is and a kazayis. Can you please shed some light for me? What is your opinion regarding this gemara? Is my question somehow not relevant? Please explain!
ReplyDeleteahg asked for the source regarding eating two kezeisim for motzie/Matza
ReplyDeleteIt all starts it Berachos 39:, where the Gemara gets into priorities in berachos, e.g. you have a whole loaf of barley bread and a broken piece of wheat bread. Which do you make the beracha on? The Gemara than says that on Pesach, put the broken matza "in" the whole one and make the beracha. Why? Because matza is called "lechem oni."
The Rishonim disagree what the Gemara means by this. Is the Gemara saying to make the beracha of al achilas matza on the broken one (middle), or is it saying to make the beracha of hamaotzi on it, leaving the al achilas matza for the whole one (top). See Tur 475 with Beis Yosef for who says what.
At the end of the day, we're left with a machlokes which matza is the mitzva one. Therefore, the Shulchan Aruch 475:1 says to eat a kezayis of both matzos. To avoid one being a hefsek between the beracha and the "real" one, it says to swallow them simultaneously, something almost impossible to do without knowing how big (small?) a kezayis REALLY is.
The Mishna Berura there (11) says that obviously, if only one kezayis is eaten, then b'diavad the mitzva has still been fulfilled.
Notice that this all has nothing to do with eating two kezeisim, but rather with eating a kezayis from both the top and middle matza. Therefore, if the seder leader gives you just a small piece of each, there's no reason to eat an extra kezayis.
ahg,
ReplyDeleteThe requirement of eating two kezayisim of matzah is codified by the Tur/Shulchan Aruch and the reason for it is a machlokes achronim. I heard it has to do with the issue that you have two seperate brachas for two mitzvahs, one for hamotzi and one for achilas matzah, and each needs it's own kezayis.
Is the 6 cc volume of a zayit considered a good value for an average or larger sized olive?
ReplyDeleteParenthetically, those who insist on large shiurim base themselves on their estimate of the length of an ama (and etzba). One can easily calculate the volume of a revi'it based on the etzba - as does the relevant gemara. It is 10.8 cubic etzba'ot. If an ama is 18 inches, then an etzba is 3/4 inch, and a cubic etzba is 0.42 cubic inches or 6.9 cc. 10.8 cubic etzba'ot are then 74.7 cc, or 2.5 fl. oz. If a zayit is 6 cc, as claimed, that corresponds to 0.2 fl. oz. On the other hand, some would have an etzba of 1 inch. That increases the minimum volume by a factor of 4/3 cubed or 2.4. A minimum revi'it is then 6 fl. oz. The latter value, or something close to it, is what made some consider that they needed to double the volume of our eggs so that the talmudic equation of 1 revi'it = 1.5 eggs is replaced by 3 eggs = 6 fl. oz. This estimate of an average etzba is an exaggerated value, which is then made much worse when it is cubed to provide a volume measurement.
Shmuel, I don't understand your question.
ReplyDeleteThe gemara in arbei pesachim (I don't remember where, but I'm sure you do) that mentions a certain town used a cup to measure out the size of the revi'is for pesach or kiddush etc. Does that not seem to imply they measured and didn't simply approximate?
ReplyDeleteBut a revi'is is not something that you can visualize in the same way as an olive.
ReplyDeleteso your argument is ONLY regarding a kezayis? You agree with my proof?
ReplyDeleteand why is the volume of a revi'is harder? That seems like a weak distinction...
ReplyDeleteA revi'is is an actual amount, and can therefore be measured exactly using a measuring cup. A kazayit by definition is an approximation.
ReplyDeleteShmuel:
ReplyDeletePerhaps you mean this gemara in Pesachim 109a?
Rabbi Yitzchak said: The xestes {a standard measure, somewhat less than a pint} for muries {fish hash} in Tzippori was equal to the log of the Temple, and with it we measure the reviit {=1/4 of a log} for Pesach.
Rabbi Yochanan said: The ancient tomanta in Teveria was greater than this by 1/4, and with that we measure the reviit for Pesach.
fantastic! chag sameach!
ReplyDelete"Volume is not density, so the pit is not relevant"
ReplyDeleteI am not sure why I am bothering to respond. Just think again for a second, pits also have volume. The gemarah in fact says that if you take out the pit and eat just the olive you don't make a bracha achronah.
Ok, now lets have a picture of a rationalist pesach kitchen. The space ship style is so insipid. Can you post a picture for us?
ReplyDeleteThank you JoshWaxman, that is indeed the gemara I meant, but R' Slfkin I'm sure knew where the gemara was, that is not the problem. The question I am asking is how to differentiate between a revi'is and a kezayis. I have been given two answers to this question, one by R' Slifkin: "Natan Slifkin said...
ReplyDeleteBut a revi'is is not something that you can visualize in the same way as an olive" the second is by EDTeitz: "EDTeitz said...
A revi'is is an actual amount, and can therefore be measured exactly using a measuring cup. A kazayit by definition is an approximation."
The first answer seems to be very tenuous in reality or rather it is underexplained; why is a revi'is harder to visualize than a kezayis?
The second answer must be proven. How do we know that a revi'is a measurement and a kezayis an approximation? In any event obviously R' Slikfin doesn't believe that; he says the difference is that one can be visualized and not the other.
Dissonace raises a fundamental question in his two comments above: How can RNS advocate sticking with chazal's view about fish [or,let us say, killing lice on shabbos] but at the same time advocate getting back to basics when it comes to the size of an olive? Is it not a contradiction?
ReplyDeletePersonally, I view the Dor Revei approach, adopted by RNS, as a cop-out. That opinion holds that the view of chazal were cannonized and thus must be followed even when we know it, or if you prefer, strongly think it, to be wrong. There is something appealing to that, because it provides Jews with a common standard, and gives us the rudimentary framework of a religious norm. If we dont adopt the Talmud as a starting off point, we'd be stuck in "each man according to what he thinks" land, ie, nowhere. However, this approach is premised on a lie, b/c Jews never "cannonized" the Talmud. Neither Jewry at large nor their representatives, if there are such, ever voted on it. The Talmud simply became the norm through the passage of time - exactly the same way the giant shiurim have become the norm, in fact. So, the Dor Reveii approach is comforting, but intellectually dishonest.
I dont really know how to avoid this problem. I'd love to say we should simply use common sense, but that would confront us with making massive changes in traditional practice, not a good idea. [Like my personal pet peeve, yom tov sheni, which common sense tells us should have been abolished long ago.] Maybe we have to say the the Dor Revii's approach is like democracy: the worst way of dealing with the problem, except for all the other ways that have been suggested.
Shmuel - the concept of a "kzayis" and a "revi'is" are two fundamentally different concepts. It's the difference between saying that something is "one meter long" and that something is "the same length as an arm". Without some explanation or background, there is no way anyone can figure out what "one meter" means. An "arm", on the other hand is clearly understood - it just raises a whole separate set of questions, especially "whose arm?" The question being discussed here regarding a kzayis is "which olive" (and, equally important, why historically many (most?) poskim didn't raise that question and instead came up with a way of measuring the kzayis in the same way as a "revi'is" or as a "meter".) But everyone agrees that a "revi'is" can't possibly be understood without some sort of explanation. This is what Rabbi Slifkin meant when he said that an olive can be visualized, while a revi'is can't.
ReplyDeleteShmuel:
ReplyDelete"why is a revi'is harder to visualize than a kezayis"
Do you have a lug lying somewhere around your house? Okay, now divide it by four. There you go. Reviis.
You are all missing the point of Kezayis inflation.
ReplyDeleteIt exists so that a tinok shenishba can go and eat a burger at McDonalds and not be oyver eating a kezayis of nevelah.
to "er"
ReplyDeleteYou should know you are not alone in considering the Dor Revi's approach inadequate. To quote R' Hershel Schachter VERBATIM: [the Dor Revii's approach is] "קשה לקבלו". I am curious whether there is any contemporary posek who DOES accept it as adequate?
To er and Shimon S.,
ReplyDeleteI beg your pardon but there is something I don't understand. Since a lug is the equivalent of six eggs, one quarter of that is an egg and a half. Why is one and a half eggs harder to visualize than an olive? If you would like I can convert it to olive measurements (1 egg = 2 olives I think) then simply think of 3 olives! Is 3 harder than one?
"The second answer must be proven. How do we know that a revi'is a measurement and a kezayis an approximation?"
ReplyDeleteA reviis is 1/4 of a hin, a measure of some sort stated in the Torah, just as the "shekel hakodesh" is also obviously some specific weight. So obviously a reviis is something somewhat precise. I say somewhat, since obviously there are always more minute units of measure, and I don't think anyone will suggest that a hin (or any liquid measure) intends it down to the molecule. But it is something you can measure, for it *is* a measure.
A kezayis is an amount comparable to an olive, hence the name. There obviously is no one thing which is an olive. If Hazal had meant a platonic olive and it had an exact measure then they would have indicated this somehow, but they never did.
Obsessing over the precise emeasurement of an olive is akin to using an atomic clock to determine shekiah. It's applying modern standards to conventions developed long before the standards were invented.
ReplyDeleteStart from the assumption - taught to us by chazal - that we have an obligation to daven shachris in the morning. Q. How do we define morning? A. We use chazal's definition of that, even though in modern times it makes no sense. [eg, why should morning start at sunrise, which can be 7.30 or later during the winter in parts of the USA, when men have been up and working for an hour and a half or more already?] So if we are already playing by chazal's book, let's do it all the way and determine the hours the same way chazal did - by APPROXIMATION. Thus, when it looks dark, it's night. When it's light, its dawn/sunrise. Just because we CAN use the Naval academy to get precise measurements, doesnt mean we should.
Shmuel,
ReplyDeleteYour questions make sense once you know what the Mefarshim say. Yet the Gemara in Pesachim 109 does not bring the connection between Lug and Beitza and ends with a calculation using Etzbaos.
The Gemara never defines the connection between Beitza and Kezayis (other then stating that Beitza is definitely MORE then 3 times Kezayis.
To "S"
ReplyDeleteYou cannot simply pasken that Chazal didn't mean a platonic olive because otherwise they would have said so. You are involving yourself in a debate of poskim that goes to back to the Geonim, whether chazal meant a specific olive or the olive of your time. Your personal inclination doesn't carry weight in this discussion. I haven't seen one good response to Shmuel. Why are three olives hard to approximate?
Friedman:
ReplyDelete"I haven't seen one good response to Shmuel. Why are three olives hard to approximate?"
And the Gemara says that three olives equals a revi'is?
Did the amoraim not know what the meforshim say? Why would the amoraim NOT describe the revi'is in terms that we can visualize? What you are saying is that Chazal arbitrarily decided that a revi'is is a measurement and a kezayis is an approximation. WHAT IS THE DIFFERENCE?! Please someone help me here, I am at wits end! Does no one have an answer?!
ReplyDeleteShimon S.
ReplyDeleteI also don't see here a good answer to Shmuel's question. The fact that the gemara doesn;t label it as three kezaysim is the REASON it isn't an approximation?! The gemara in pesachim itself clearly says it isn't. That's not the question, the question is why! Since we don't see a why then probably what is true for a revi'is is true for a kezayis!
Shmuel:
ReplyDelete"Did the amoraim not know what the meforshim say?"
Since there is a big disagreement among the Rishonim about the shiurim, I don't see the meaning of the question. Did the Amoraim know the Rambam? Did Rashi?
"Why would the amoraim NOT describe the revi'is in terms that we can visualize?"
They did the best they could: 2 fingers by 2 fingers by 2,7 fingers (Rav Chisda, Pesachim 109a). You don't find a lug in an average household.
You bring the shittos of the Acharonim as facts and wonder why the rest of us doesn't see it in the Gemara... Try to work the way from the Gemara (or earlier sources) onward.
Pinchy Cohen:
ReplyDelete"Since we don't see a why then probably what is true for a revi'is is true for a kezayis!"
And WHY did the Rambam feel the need to translate the ancient lug into contemporary dirham measurements but didn't feel any need whatsoever to define an olive?
Again: Olive is a fruit of the olive tree. What is a lug? How would a shoemaker or farmer in Tzippori know how much is a lug?
Shmuel:
ReplyDeleteIt is important to cite one's sources and lay them out fully, before expecting others to respond. I think the full context should have completely dismissed the question.
Given that there were two different opinions as to what the log was (where one 1/4th more than the other), then it makes sense for R' Yitzchak and R' Yochanan to say "with this we measure the reviis". That is, we use the standard log measurement of town X or Y to determine a log, and take a reviis of this. That does not mean that they physically used this vessel to measure out their reviis. It was establishing what the measure **was**, in a machlokes! So I don't see where your question even begins.
Why they had such a standard log? For commerce, most likely.
The other answers given are good and defensible (a 1/4 of some arbitrary measure is not as intuitive as a "kezayis"), but one need not even get that far.
Unless I am missing something here, which is certainly possible.
DF:
ReplyDeleteActually, your analogy refutes your theory. I think it's Rashi in Megillah who says that even though the day starts at dawn, you must wait until sunrise to perform mitzvos of the day in order not to end up doing them too early. In other words, we don't rely on your approximation.
Of course, the kizayis is based on approximation, but if you end up eating too little, you don't get that check in shamayim anymore than a guy who davens shacharis before dawn.
So, while there is absolutely no need to obsess over it, if you just want the minimum for whatever reason, there's nothing wrong with measuring. If it's early morning and it's hard to tell if it's the break of dawn, there's nothing wrong with looking at a clock.
Joshwaxman, I was a bit surprised that you didn't mention what you wrote in your blog many many years ago :)
ReplyDeletehttp://parsha.blogspot.com/2006/04/measures-of-reviit-in-bavli-vs.html
The Talmud Yerushalmi, and the Talmud bavli have different measurements for the reviit, because they use a different number of tfachim for their Amot. Which means that even in the Gemorah, the Lug/hin was not exactly known what size it was supposed to be. Despite the ambiguity, they still used exact measurements.
I'm also commenting because nobody has given the obvious answer as to how we know that a Kzayit is an approximation, and a Hin or Reviit or Maneh (used for measuring the Mincha offerings of dry goods) are measurements.
The word Kzayi means "Similar to an olive". We do not say "KReviit", or "Khin". The kzayit is by definition close to, but not exactly the size of something.. ie. an approximation. A reviit on the other hand, is a reviit, and we do not measure k'reviit.
Why are things that are measured in Kzayits approximations while things measured in Riivit are exact measurements? Becuase some things are measured, and some things are estimated. How much does a bale of hay weigh? How much does a Kilogram of hay weigh?
Given that (as you pointed out) R. Chaim of Volozhin would approve of this chart - shouldn't the post be entitled "Matzah/ Maror Chart for Rationalists and Kabbalists"
ReplyDeleteJr. - That Rashi you cite does not refute my point. There was no way to give a pinpoint time for sunrise, or anything, before the spread of clocks in the mideival period.
ReplyDeleteAs for your contention - "if you end up eating too little, you don't get that check in shamayim anymore than a guy who davens shacharis before dawn" - we fundamentally disagree, and of course, as a matter of belief, proof is both impossible and irrelevant.
I heard someone mention that they invariably end up eating enormous "kezeisim" at their Sedarim.
ReplyDeleteYoung men often show off by eating large amounts in small amounts of time. This at least gives them a way to do so that's kosher.
Too bad they're not encouraged to eat a different shirt each year as a teaching device... "this year at Seder, follow the shittah of R' Ploni" instead of winding up in a place where a problematic chumra has become a chazaka.
DF:
ReplyDeleteOk, so please explain that Rashi. Why say to wait until sunrise at all, if the starting zman is dawn. Until you explain that, I consider it refutation of both your points.
I'm not sure how people can possibly confuse this. Chazal legislated the kezayith. What they meant by that term is quite clear despite the confusion (or feigned confusion) of some people here. But assuming (incorrectly) that that wasn't clear, there are then multiple opinions about how to quantify what they meant, all within halacha, all stated by rishonim acharonim etc. NO ONE IS EDITING WHAT CHAZAL SAID OR WHAT THE TALMUD CONCLUDED.
ReplyDeleteThe fish or the lice on shabbat on the other hand, are issues where some people suggest adopting the minority view or a different view from chazal since the chazal were wrong about it (in their reasoning of the law) while Rabbi Slifkin adopts the approach that we don't change the law based on that.
With the case of olives and kezayith, chazal were not wrong about anything. So that doesn't compare to the fish or lice.
This isn't "Rationalist Judaism", but Empiricist Judaism.
ReplyDeleteSince halakhah is a legal system, not a set of empirical claims, you would need to prove that the accepted range of shitos for a kezayis are actually less binding just because they were based on empirical errors. Perhaps they have legislative weight anyway.
Doesn't the Rambam say as much WRT the shemittah year handed down by the geonim? The year has to be wrong -- if you do the math, there is no accounting for yovel years being omitted back when yovel was deOraisa. And yet, being empirically wrong doesn't mean the Rambam defies or redefines the tradition. It's *rational* to obey legal authority on a legal question, and a leap of faith to assume without feeling a need to justify the notion that the legal process can be ignored when a gap opens between the law and physical evidence.
One possible "out" in this example, if not in general, is that the range of commonly accepted values is large -- just shy of a factor of 2. I am inclined to say that if the observant community accepts a range of values, it's binding. But that's not necessarily so -- perhaps a range of values means no one version of kezayis has the legal weight of a commonly accepted opinion.
(My argument against has to do with other cases of ranges, in particular our "acceptance" of Talmud Bavli or of the Greater Shulchan Arukh. It's not that we always hold like either text, but that they define a center of a range of acceptable values. And one needs increasing amounts of justification the more one veers from them.)
Second, I agree with those who dubbed your purim spoof of RMJB and now this "chart" to be leitzanus. It's an attempt to use sarcasm to do an end-run around reason. The opposite of rationalism.
There was never any legal authority to change what chazal instituted as a minimal eating. They said kezayith and they meant kezayith. In fact, nobody has changed it. Some became confused about the size of an olive but we see there is very little reason for confusion about that.
ReplyDelete"Accepted range of shitos" is just what you determined in your mind is "accepted" a priori. If you define the erroneous view that distorts chazal as "accepted" and anything else as "not accepted," then of course you should expect to find yourself in a bind and unable to embrace the simple meaning of chazal about olive sized portions.
Merely pointing out the absurdity of your position (as the chart does) does not constitute leitzanus. It is a thought provoking way to present the absurdity in a visual manner that is immediately grasped. I think it is leitzanus when people here try to tell me olive size means grapefruit. While we're at it, up is down, and left is right - pure leitzanus.
Actually, you've all been reading it wrong. According to the oldest manuscripts, it is not כזית. It is כ' זית.
ReplyDelete