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The Mitzva to Eat Matza and the Measurement of a Kezayit (2)

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(Translated by David Silverberg) 

In part one of the shiur, we learned that even nowadays, in the absence of the Bet Hamikdash, there exists a Biblical obligation to eat matza at the seder.  The accepted - albeit puzzling - ruling is that of the Rosh, that one must eat two kezeitim-worth of matza, but the consumption of the second kezayit is on a lower level of obligation.  We then proceeded to examine the measurement of "kezayit," and we found a difference of opinions on various levels: whether a kezayit is a half or a third of a kebeitza, whether the size of a kebeitza in this regard is determined with or without the eggshell, and whether or not to assume that our eggs and olives are half the size of those used in Talmudic times.  If so, as the Noda B'Yehuda contends, then for practical purposes we must double all halakhic measurements.

 

IV. The Measurements According to Modern Day Standards

 

Kebeitza (With its Shell)

 

     According to Rav Chayim Na'eh (as we saw in Part 1), a kebeitza amounts to 57.6 cubic cm (according to the Rambam's calculation of a kebeitza; but based on the Turkish dram, as we saw in Part 1), while according to the Chazon Ish it equals 100 cubic cm (for as we noted, one egg equals 50 cubic cm, and the Chazon Ish maintains that the measurements must be doubled). 

 

Kezayit

 

     As we have seen, the Rishonim dispute whether a kezayit is a half a kebeitza (Tosafot) or only a third (Rambam).  We also saw that if a kezayit is a full half of a kebeitza, then we do not include the egg's shell - which is estimated as 1/20 of the egg's entire volume - for the purposes of this calculation.  Thus, it turns out that according to Rav Chayim Na'eh an egg without its shell equals 54 cubic cm, and thus a kezayit - according to Tosafot, that a kezayit is half a kebeitza - is 27 cubic cm.  According to the Chazon Ish, however, an egg without its shell amounts to 95 cubic cm, and thus Tosafot's kezayit would equal 47.5 cubic cm.

 

     As we have seen, within the Rambam's view, that a kezayit is only one-third of a kebeitza, the shell must be considered when figuring a kezayit.  Thus, for Rav Chayim Na'eh, who calculates the egg's volume with its shell at 57.6, the Rambam's kezayit is one-third of that, or 19.2 cubic cm.  (In actuality, however, Rav Chayim Na'eh was even more lenient and estimated a kezayit as 17.3.  Recall that the position that maintains that a kezayit is one-third of a kebeitza argues its case based on the Gemara's assessment of a "gerogeret" as one-third of a kebeitza, and a gerogeret is somewhat larger than a kezayit.  Therefore, a kezayit is, in essence, even less than one-third of a kebeitza.)  According to the Chazon Ish, that an egg with its shell amounts to 100 cubic cm, the Rambam's kezayit equals 33.3 cubic cm.

 

Volume or Weight?

 

     The Rambam (Hilkhot Chametz U'Matza 5:12) defines "shi'ur chala" (the minimum amount of dough that requires the separation of "chala") as approximately 43.5 eggs, and he adds, "like the body of an average egg - not its weight."  As the Maggid Mishna explains, the Rambam here establishes that these measurements are determined by volume, not weight, a principle that seems to emerge as well from the mishnayot (Keilim 17:6 and elsewhere) and many other sources.  This is also the view of the Mishna Berura (486:3).  However, the Kaf Hachayim (168:46) observes that common practice was to calculate according to weight, seemingly against the straightforward reading of all the poskim.  We may perhaps attribute this practice to the difficulty involved in constantly measuring volume.

 

     Today, Ashkenazim calculate volume, in accordance with the aforementioned ruling of the Mishna Berura, and this is also the oft-cited view of Rav Yosef Shalom Elyashiv.  The Sefardic authorities dispute the issue: Rav Ovadya Yosef (Yechaveh Da'at 1:16) writes that the weight measurement should be used, while Rav Shalom Messas ("Tevu'ot Shemesh") maintains that we determine measurements based on volume.

 

     If we measure based on volume, a question arises regarding the empty spaces in the matza.  Generally speaking, when measuring volume of a hollow mass for halakhic purposes, the empty space is not taken into account. When there is swelling in the given item, the empty space of the swelling is the subject of controversy that surrounds the mishna in Uktzin 2:8.  The Mishna Berura (486:5) rules that regarding natural swelling, one can be lenient and include in his measurement even the empty air-pockets.

 

V.   The Bottom Line - The Measurement of "Kezayit" for Matza at the Seder

 

     A machine matza generally weighs 30 grams, and its volume is 60 cubic cm, meaning, its specific weight is .5 (Midot V'Shi'urei Torah chapter 17, p. 277).  Many people eat specifically hand-made matza (at least for the first kezayit), whose weight differs substantially from machine matza.  Its specific weight, however, is similar to that of machine matza, and thus one may calculate the required amount based on the measurements of machine matza.

 

     Based on our discussion, there emerge three possible amounts for a kezayit of matza:

 

1)  The largest amount: half a kebeitza according to the position of the Chazon Ish - three-quarters of a matza.

2)  The medium amount: half a kebeitza according the position of Rav Chayim Na'eh - half a matza.

3)  The lowest amount: one-third a kebeitza according to the position of Rav Chayim Na'eh - one-third of a matza.

 

Now, let's go one by one through the various points at the seder when matza must be eaten, and see how much matza must be consumed each time:

 

The first kezayit: This consumption of matza fulfills the Torah obligation of eating matza on Pesach night.  Therefore, it is proper to follow the stringent view and eat three-quarters (or at least a half) of a matza.

 

     One should bear in mind that this first kezayit must be eaten within a time frame called "kedei akhilat peras" from the moment he recites the berakha.  There is much discussion surrounding the definition of this time frame, the most accepted view is four minutes.  It would seem, however, that this discussion is irrelevant for practical purposes, so long as one eats at his normal rate of consumption without any interruptions, bearing in mind that the one "goal" before him at this moment is the consumption of a kezayit of matza.

 

The second kezayit: (eaten together with the first) As we saw towards the beginning of our discussion, this second kezayit is eaten only as an added stringency (and its level of obligation is therefore even less than that of a rabbinic enactment).  As such, we may be lenient with regard to its size, and eat only one-third of a matza.  We may add a further leniency, to view the three-quarters of a matza eaten for the first kezayit as consisting of two kezeitim (one-third of a matza each), and thus eat three-quarters of a piece of matza for both kezeitim.  This view is cited in the name of Rav Elyashiv and Rav Nissim Karelitz (Siddur Pesach K'Hilkhato chapter 8, note 24).

 

Korekh: This obligation is "miderabanan" (rabbinic legislation), as a commemoration for the manner in which the korban Pesach was eaten in the Bet Hamikdash.  Therefore, we may adopt the middle position (which assumes that the measurements have not decreased in size - see earlier in our discussion) and eat half a matza.  One for whom even this involves difficulty may eat one-third (see Mishna Berura 486:1).

 

Afikoman: Although strictly speaking even one kezayit suffices for eating the afikoman (Shulchan Arukh 477:1), one should optimally eat two kezeitim (Mishna Berura ad loc.).  Therefore, what we said earlier regarding the second kezayit applies here, as well.  Namely, one may eat three-fourths (or at least two-thirds) of a matza and view it as consisting of two kezeitim.  If, however, one feels that such an amount would constitute excessive eating ("akhila gassa"), he may eat half a matza, or at least one-third of a matza (see Mishna Berura 486:1).

 

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