Or, Avoiding Unnecessary Strictness on Passover....
Have I eaten enough maror (bitter herbs)?
Well, how much matzah do we have to eat in order to fulfill the mitzvah?
One washes one’s hands, and says the blessing “on raising the hands” and takes the matzah in the order in which one put them, the broken one between the two whole ones, and holds them in his hand and blesses “hamotzi” and “on eating matzah” and then breaks the top whole one and the broken one . . . and eats them while reclining, an olive’s bulk of each. If one is unable to eat two olive’s bulks at once, one eats the “hamotzi” first, and then the “on eating matzah.” (Shulhan Arukh, Orah Hayyim 275:1).
The source of this ruling: There is no “eating” with less than a kezayis (equivalent to an olive). (Toras Kohanim, Acharei 12:2; Emor 4:16).
“An olive’s bulk” . . . and the later authorities agree that one only needs to put both olive’s bulks in his mouth at once, and to chew them, but one does not need to swallow them at once, but it suffices to swallow about one olive’s bulk first, and then swallow the other. And even if he swallowed it a little at a time (bedei avad) as long as he did not delay from beginning to end longer than it takes to eat a half loaf (kedei akhilat peras) (Mishneh Berurah note 9)
And how much maror?
After that one takes an olive’s bulk of bitter herbs, sticks it entirely into the haroset, and does not leave it there in order not to weaken the bitter flavor. For this reason one should shake the haroset off it, says the blessing “on eating bitter herbs” and eats it without reclining.
After that one takes the third matzah and breaks it off, and combines it with the bitter herb, and dips it in haroset (Rama: some say we do not dip it, and that is the custom, and so I have seen people do) and says “In memory of the Temple, like Hillel, and one eats them together while reclining. (Shulhan Arukh, Orah Hayyim 275:1).
After finishing the meal each one eats an olive’s bulk of the matzah shemurah from under the tablecloth, in memory of the Pascal sacrifice that was eaten when satisfied (Shulhan Arukh, Orah Hayyim 277:1)
Be’er Heiteiv on the above ruling, note 1: The late rabbis agree that ideally one should eat two olive’s bulks, one in memory of the Pascal sacrifice, and one in memory of the matzah that was eaten with it; but in any event, one must certainly eat an olive’s bulk.
So how big is an olive’s bulk?
According to the OU Guide for Passover 2016 5776:
Rav Chaim Noeh
Kezayit Matzah = 29 cubic centimeters
Kezayit Maror = 19. 3 cubic centimeters
Rav Moshe Feinstein
Kezayit Matzah = 43.2 cubic centimeters
Kezayit Maror = 32 cubic centimeters
Kezayit Matzah = 50 cubic centimeters
Kezayit Maror = 33.3 cubic centimeters
1 cubic centimeter = a bit less than 0.034 ounces.
Maror is a rabbinic mitzvah, when we do not have the Pascal sacrifice, so the rabbis use a more lenient unit for determining the volume of a kezayit. Matzah is a Torah mitzvah even today, so the rabbis use a stricter unit.
However, according to the Mishnah, “the olive that we mention is not a big one, nor a small one, but a medium-sized one, and that is the Agori.”
M. E. Kislev, Dept of Life Sciences, Bar-Ilan University, estimates that the commonly- published sizes for Kezayit is “about ten times greater than the volume of a common fruit olive.” (M. E. Kislev, “An Olive Bulk: The Olive Fruit as an Ancient Unit of Capacity”).
According to Prof. Kislev, Israel now has three distinct varieties of olive, from largest to smallest, Nabali, Souri and Mallissi. He notes that only the Souri, the middle-sized variety has fruit that can remain on the tree through the winter. This fits the description of the Egori olive “Why is it called Egori: Because it keeps its oil while all the others lose their oil. R. Hanina said: all olives, when rains wet them, lose their oil, and this one, rains . . . and it keeps its oil” (Yerushalmi Bikkurim 1:3 on 63, 4)
Archeological evidence shows that ancient Israel used Souri olives, as researchers have found the pits of different varieties at sites in Israel. The ancient Souri olives, based on the pit size, had about 3 cubic centimeters of volume, as do modern Souri olives.
More than a thousand years ago, the Geonim of Bavel were asked about the size of kezayit. (Teshuvot HaGeonim, Harkavy edition. Cited in Kislev “’Kezayit’ Pri HaZayit BeMidat Nofah” 435):
That which you asked about the unit of a large fig, or a medium fig, and so a large olive, a small olive and a medium-sized olive, they are themselves units, and how can one give a unit for the unit? If you suggest it is a unit of weight, our rabbis did not give a precise weight, and the holy One did not require us to be precise with weight, but each one of us will go according to his opinion and fulfill his obligation. We do not need to derive another unit. Rabbi Yehudah says: how do we estimate a medium size? We take the biggest of the big, and the smallest of the small, and average them. Rabbi Yossi says, who will tell us what is the biggest of the big, or the smallest of the small? Rather it all goes according to the opinion of the person who looks.
Also in the responsa of the Geonim appears the notion that the units never appear in weights, since governments can change the weights of their units at will, and who can recover the ancient meaning of the weights. Rather the units come in olives because everyone can see how big an olive is (Slifkin 5).
My wife conducts an informal survey of Jews our age and older by asking, “How much matzah did your grandfather break off for each participant at the earliest seder you can remember?” Invariably people answer by showing a small size, approximately consistent with the bulk of a modern medium-sized olive.
So how did we get to the giant kezayit?
Rambam, Hilkhot Eiruvin 1:9 says that a dried fig is about 1/3 of an egg. The Talmud, Shabbat 91a, says that an olive is smaller than a dried fig. So it follows that the olive is less than 1/3 of the size of egg, according to Rambam (Slifkin 7; see Mishneh Berurah 486:1). Rambam uses a chicken egg as his unit of measurement in the entire Mishneh Torah (Hilkhot Shabbat 8:5).
A Spanish rishon, Rashba, gives the size of an egg as much more than four olives. Another Spanish rishon, Ritva, says that a dried fig is the size of several olives. His olive is thus about 1/9 of an egg, at the upper limit (Slilfkin 8).
A statement in the Talmud (Keritot 14a) asserts that the human gullet holds no more than two olives. Another statement, (Yoma 80a) asserts that the human gullet holds no more than one egg. How do these two statements relate to each other?
Tosafot (on Hulin 103b “Halko Mebahuts”) proposes that a kezayit equals half a chicken’s egg in volume (I have seen the claim that Tosafot means a dove’s egg, which would make his measure close the Rambam’s less than 1/3 of chicken egg.) The two measures fit together perfectly. The composers of Tosafot, living in what is now Northern France and Germany, probably did not have experience with actual olives, which may have made the proposal seem plausible.
Rabbi Joseph Soloveitchik replied to a student: “K’zayis? How big is a k’zayis? I don’t know. But I know a k’zayis is according to most rishonim is a chatzi beitzah (half and egg) and according to [Rambam} is one shlish of a beitzah (third of an egg), and I know that elephants don’t lay eggs.” (Holzer 185).
We do not have excellent archeological evidence for the size of eggs in the ancient and medieval world. Unlike olive pits, eggs do not keep. Kislev believes that chickens in the Greek-Roman period were about the size of modern Leghorn chickens, and so he estimates the size of a chicken egg in the Greek-Roman period as about 57.6 cubic centimeters. If so, the estimate in Tosafot would have a kezayit at a huge 28.8 cc.
Kislev proposes a different resolution to the two estimates of the size of the gullet. Perhaps we cannot swallow more than two hard items of about 3 ccs, such as olives or hard candies, in one gulp, but we can swallow a much larger soft item, such as an egg (perhaps a raw egg?) (Slifkin asserts that Rabbenu Tam made this same point in a Tosafot on Eiruvin 82b).
Shulhan Arukh Orah Hayyim 486 states: “The amount ‘kezayit,’ some say is half an egg.” Usually, Shulhan Arukh uses the expression “some say” after stating the more definitive position. Here, he leaves “half and egg” unchallenged. Perhaps he feels it superfluous to mention the definitive position, that a kezayit is the same size as an olive.
In Talmud Pesahim 109a, when asked about revi’it required for the cup of wine on Pesah, Rav Hisda rules “the revi’it of the Torah is two fingers by two fingers to the height of two fingers and half finger and a fifth.”
Rav Steinsaltz reports that the unit, “a finger,” gets measured across the thumb at the widest part of the thumb.
Rabbi Yehezkel Landau (1713-93) measured this size in cubic thumbs, according to the Talmud in Pesahim (120a), and compared that with the measure of volume given in eggs. The numbers did not match. He concluded that the eggs of ancient Israel must have been twice the size of modern eggs, for it seemed impossible that thumbs had grown. If so, we should double our measures for all mitsvot related to volume of eggs.
One of his students maintained that Rabbi Landau himself was a tall man, and had broad thumbs. According to R. Frank, Rabbi Landau set the width of a thumb at 2.4 centimeters.
Rabbi Avraham Na’eh set the width of a thumb at 2 centimeters, which yields a revi’it of 86.4 cubic centimeters, extremely close to the size of an average egg and a half (using Kislev’s estimate for the size of a chicken egg, 57.8, then 1.5 eggs equals 86.7 ccs).
Using Rabbi Landau’s measure for the width of thumb, 2.4 centimeters, the revi’it comes to just under 150 cubic centimeters, just about twice as large as a modern egg and a half.
Combine that theory with the conversion table that an olive is half an egg, and one gets the modern Ashkenazi giant kezayit.
Is this enough wine?
The size of the cup should be one Revi’it (a quarter of a log) after it has been mixed with water (Rama: if one wishes to mix it) and one should drink most of it or all of it. If it has many Revi’yot, as many people may drink from it as it has Revi’yot. Some say one must drink most of the cup even if it has many Revi’yot. (Rama: and one must drink this amount without much interruption in between) (Shulhan Arukh Orah Hayyim 272:9).
“Without much interruption” That means he must not delay from the beginning to the end more than the time it takes to drink a Revi’it . . . Magen Avraham writes that if he delays longer than the time it takes to eat half a loaf (kedei akhilat peras) he has not fulfilled his obligation and must return and drink (Be’er Heiteiv note 13).
A Revi’it. But how much is a Revi’it?
According to the OU Guide for Passover 2016 5776:
Rav Chaim Noeh – 3 ounces
Rav Moshe Feinstein – 3.3. ounces
Chazon Ish – 5.3 ounces
One ounce = just a little less than 30 cubic centimeters.
The amount of a Revi’it is 1½ eggs. If we take Kislev’s estimate for the volume of an egg at 57.8 cubic centimeters, then a Revi’it has to be somewhat under 3 ounces.
Notice all the difficulties in estimating the average size of a chicken’s egg under modern conditions. The eggs that we see in the supermarket do not represent a random selection of eggs. Smaller eggs get made into powder or otherwise diverted from the consumer market. If we have a good way to estimate the modern egg, that may serve as our unit. If we decide to use the ancient egg as our unit, how can we extrapolate with any confidence to the size of ancient eggs?
How long does “as long as it takes to eat half a loaf” take?
Rambam describes a “peras” as 3 eggs, half the standard loaf of six eggs. As long as it takes to eat half a loaf thus means the amount of time it takes to eat a piece of bread with the volume of three eggs.
Rashi rules that a “peras” means 4 eggs. I have seen the claim that these are dove eggs rather than chicken eggs, in which case his unit essentially agrees with Rambam. I have not found a source to substantiate that claim. Even if his unit is chicken eggs, the period in which we are to consume our matzah or drink our wine remains constricted.
Does as long as it takes to eat a half loaf mean, when one is speed-eating, or does it mean, when one is enjoying a leisurely lunch?
Finally, in practice:
For a sick or elderly person who has trouble eating that much, we should rely on the minimum amounts. The olive’s bulk of matzah should equal about enough matzah to make a life size-statue of a medium size-olive. The olive’s bulk of maror should contain about enough lettuce to make a life-size statue of a medium-size olive. The cup of wine should hold a small revi’it, about 3 fluid ounces.
A healthy person, who has built up an appetite during the long section of the Haggadah retelling the story, and who wants to do the mitzvah with enthusiasm, should eagerly eat more than a mere olive’s bulk (or two, where the authorities recommend that), but this person has no need to try to bolt the food down as fast as possible. One should eat at a reasonable pace, like a person enjoying the bounty of the Giver of all blessing, and like a person enjoying the experience of becoming sanctified by performing a commandment.
Frank, R. Yitzhak. The Practical Talmudic Dictionary. Jerusalem: Ariel, 1994, 1991.
Holzer, R. David. “Insights from the Rav on the Seder,” The Medieval Haggadah Anthology Jerusalem: Holzer Sefarim, 2014.
Kislev, M. E. “An Olive Bulk: The Olive Fruit as an Ancient Unit of Capacity” in M. Heltzer and D. Eitam. Olive Oil in Antiquity: Israel and the Neighbouring Countries from Neolith to Early Arab Period. Conference, 1987, Haifa.
Kislev, M. E. “’Kezayit’ – Pri HaZayit BeMidat Nofah” Tehumin 10, 5749. 427-437.
Slifkin, R. Natan. “The Evolution of the Olive: The Halakhic History of the Expanding Kezayis.”
Steinsaltz, R. Adin, A Reference Guide to the Talmud. New York: Random House, 1987.