Thursday, March 31, 2022

The Kezayis Revolution Continues!

Good news for the Jews! The recent trend of insisting on ever-larger sizes of matza that need to be eaten on Seder night continues to be challenged. The latest work, released into the public domain, is called Zayit Ra'anan, by a Sefardic Torah scholar. You can download it at this link. I haven't had time to study it properly, but the numerous haskamot alone are fascinating in their diversity. Some of the rabbanim are greatly unnerved, some admit that the arguments seem compelling but are afraid to say that anyone other than "the Gedolim" can decide these things, and others forthrightly state that it is obviously true that a kezayit is the size of a contemporary olive.

The monograph that I wrote on the evolution of the kezayis, from the size of an olive to a matzah ten times that size, seems to be the most popular piece that I have ever published. It's now incorporated in my book Rationalism vs. Mysticism, which you can purchase at this link.

Here is a list of other posts relating to this topic:

Matzah/Maror Chart for Rationalists - so that you, too, can have a chart!

The Popularity of Olives - exploring why this paper is so popular and yet hated by some.

Why On Earth Would One Eat A Kezayis?  - discussing the strange notion that one should aim to eat a kezayis of matzah on Seder night.

The Riddle of the Giant Kezayis Defense - wondering why many people would not accept that a kezayis is the size of an olive.

Maniacal Dishonesty About Olives - exposing an error-ridden critique that appeared in the charedi polemical journal Dialogue.

It's Krazy Kezayis Time! - discussing the view that one should eat a huge amount of matzah in a very short time in order to fulfill all opinions.

The Kezayis Revolution - announcing the fabulous sefer by Rabbi Hadar Margolin, which presents the same arguments that I brought but in a more yeshivish manner. He also brings an astonishing array of evidence that many recent charedi gedolim likewise held that a kezayis is very small, including even the Chazon Ish! Best of all, the entire sefer can be freely downloaded.

Monsters & Matzos - a great riddle: what is the connection between the relatively rare findings of ancient whale bones on the coast of Israel, and the large size of matza that many people eat on Seder night?

Meanwhile, the new Biblical Museum of Natural History is open for tours, and will be open over Pesach too. We expect most tours on Pesach to sell out, so book your tour now! Visit for more details.

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  1. The link to the chart no longer works 馃槶

  2. There's a strange irony here. I'm not sure where a sense of proportion is more lacking: Insisting a 讻讝讬转 is the size of a grapefruit, or taking 400+ pages to show it's the size of an olive.

    1. That being the case, I did glance at the 住驻专, and he did pull together some interesting sources.

  3. Thanks, Rabbi Slifkin. After reading your writings and listening to several shiurim on this matter years ago, I switched my family over to a real kazayit.

    1. Nattan is not a posek. His area of expertise is animals and mocking things that he does not understand. Following his writeup in practice is at one's own risk. Even Nattan himself states in his paper that his "correct view" of the size of a kezayit may not have any practical halachic implications. He pints out that perhaps even according to him, halacha may follows its own framework and a Halachic Kezayit would therefore be as it was understood for the last many hundreds of years.

  4. FYI: the links from the posts in 2010 and 2012 do not seem to be working:

  5. Is rabbi Margolin accepted as a reliable opinion on the matter.

    I vaguely recall seeing a kuntras from a grandson of R AC Noeh who treads quite heavily over Rabbi Margolin

    1. R. Margolin responded to them (you have to join the forum to download links):

    2. Thanks J, I have faith that you've provided a useful link

    3. Baal HaBoss, I found your response irritating at first, then gave it some thought.
      My first response was "oh my goodness, why judge the responsa by the name of the guy who wrote it? Why not actually read the discussion and see if the argument has merits??" I was angry because your response seemed to be a typical frum knee-jerk response of following the authority rather than content. Which has always seemed to me to be both inherently wrong and also un-Jewish. (As an attitude it fails two tests.讗诇 转住转讻诇 讘拽谞拽谞谉... and 讛诇讜诪讚 诪讻诇 讗讚诐.) I'm tired of seeing more liberal, but perfectly competent rabbis be mocked and disrespected because they don't pass the 'my rabbi is kosher, yours isn't' identity test. I fumed at this frum response.

      But then I calmed down. There is a place for deciding if a person has competency in a certain area of knowledge. I have no idea who Rabbi Margolin is. Maybe he's a quack. There is, apparently, no shortage of rabbis on both sides of the spectrum, who talk utter garbage and who shouldn't be listened to. And before I buy a book I want to know the background of the writer to see if there is any point to listening to what they have to say.

      In this case, there seem to be haskamot to show that Rabbi Margolin has at least some competency in this field.

      RNS, could you put up a short biog about Rabbi Margolin so we can know more about him?

  6. I'm noticing that a kezayit changes if we're talking about how much matza to eat at the Seder or how much one needs to eat in order to be obligated to say birchat hamazon.

  7. Kezayis as big as a tennis ball... April Fool's! Oh wait, it's still March...

  8. God: "Please eat matzah on pesach"

    Jews for next 2000 years argue over how much to eat

    God: *Facepalm*

  9. What exactly is your concern here? Do you really think people believe you have to have giant matzahs like your illustration picture? For at least 30 years already people concerned with shiurim have been using charts that show the matzah to be eaten as less than an 8 x 11 piece of paper. That's really not a big deal, especially for an annual ceremony which one likes to make special. Would you prefer everyone eat a cheese cracker size and be done with it?

    Same with liquids. Certain MO writers like to moan about the Chazon Ish shiur, but even if you choose to go with that shiur, and you're super 诪讚拽讚拽 to the decimal, its basically a bit more than 5 ounces, which is not all that big.

    I dont disagree with your basic premise that an olive today is an olive of yesterday, but the hyperbole you give it is typical and a little silly. Your "revolution" is a kleinekeit.

    1. "That's really not a big deal.."

      Really? Four 讻讝讬转讬诐 for each person. In 讞讜"诇, that's two 住讚专讬诐. That's eight for each person. For a family of seven, that's 56. If the 讻讝讬转 is half a hadmade 诪爪讛, that's 28 诪爪讜转 total. Now if there are 6.5 诪爪讜转 in a pound, that's 4.3 pounds. Maybe you can still get handmade 诪爪讜转 for $20 a pound. That would be $86. A smaller 讻讝讬转 would save such a family $50.

      Of course, if the family is larger and includes in-laws and grandchildren, you can easily get 20 people at the table. And if they demand some boutique 诪爪讜转 at $45 a pound, the savings is over $300.
      So, it certainly can be a big deal.

    2. R' Slifkin has written on this extensively. That you choose not to read it is your problem.

      Also, five ounces times four cups is twenty ounces. That's a *lot* of wine.

    3. For Seder night you need almost three servings of matzah. And for the 4 cups that’s over 20 ounces of wine, and to top it off if you live in galut that needs to be done over the next night.
      Maybe you aren’t a diabetic, or have a digestive disorder, or maybe you just plain like eating. However most of us want to enjoy the other aspects of the Seder, the meal and not feel like engorged, or risk a bowel obstruction.

  10. It seems to me that the whole discussion is a bit artificial. Even without the Psak Din of Rav Slifkin one can fulfill his duty with 9 gram of Matzah:

    Also the amount of wine, it is not required to drink whole glasses, but it is possible to drink a part and to refill the glass.

    And somebody with sensitivities to gluten, alcohol, sugar or anything else can consulted with his Rav and find also a way to further reduce the amounts.

    The duty is to live with them and to enjoy, and for some this is by the way of chumrot and for some not.


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