The Pesach holiday is a time where we have an opportunity to reflect on our rich heritage and affirm our commitment to the continuity of our many traditions. The geulah from Mitzrayim was the point in our great history when we were freed from bondage to man, and culminated with our becoming a nation with the subsequent acceptance of the Torah at Har Sinai. What has sustained us and preserved us throughout the millennia? Observance of Torah and mitzvos is replete with many intricate details that require us to be highly meticulous in our performance, in order to properly fulfill what is required by religious law. During Pesach, this notion expresses itself through required measurements of the special foods we eat during the holiday. These basic measurements and their careful observance are very much a part of our heritage. Indeed, the Talmud states that halachic measurements are a part of the unique laws that were given to Moshe Rabeinu at Sinai1.
The precept of matzah is fundamentally a Torah level mitzvah that requires one to consume minimally a kezais, which amounts to the size of an olive by volume. Although strictly speaking, the Torah level mitzvah of matzah requires one to eat the measurement of a single kezais, there is a rabbinic requirement to consume a total of five kezeisim at different intervals of the seder. The first two portions are eaten together, one associated with the bracha of hamotzi with the other associated with the bracha of al achilas matzah. The third kezais is eaten as part of the traditional korech sandwich from the sage, Hillel, which serves as a reminder of the Beis Hamikdash. The fourth and fifth kezeisim are eaten together at the end of the yom tov meal as part of the Afikoman. The fourth kezais is associated with the korban Pesach and the fifth is a reminder of the matzah eaten with it. Ideally, the required measurement for the additional four kezeisim should be the same as the basic mitzvah of matzah mentioned above. However, since these supplementary four kezeisim are rabbinic requirements, in an extenuating circumstance there is room for leniency to eat less. This will be discussed in somewhat further detail below.
The precise measurement of kezais is a point of dispute. Tosafos2assumes that a kezais is roughly half the size of an egg, whereas the Rambam3writes that the correct measurement is less than a third of an egg. The Rambam bases his position on the requirement that an eruv chatzeiros requires the amount of two seudos, which are collectively the measurement of 6 eggs equivalent that is also the size of 18 grogros4. Since a single grogeres is slightly larger than a kezais, the size of a kezais must therefore be somewhat smaller than a third of an egg. However, Tosafos disagrees based on the assumption that one is unable to swallow more than a single egg5or two zeisim6, at a time. Based on these two assumptions it would therefore appear that a kezais is approximately the size equivalent of half of an egg. The Shulchan Aruch7cites the opinion of Tosafos; however, Mishneh Berurah8 postulates that in the case of one who is sick, infirm, or cases involving mitzvos of a rabbinic nature, it is possible to rely on the position of the Rambam in an extenuating circumstance.
There is an additional dispute amongst later authorities whether the actual size of an egg is considerably smaller nowadays since the time of the Talmud, and whether consequently it is necessary to double the measurements in practice. This was the opinion of Rav Yechezkel Landau9, Chasam Sofer10, Chazon Ish11, Rav Moshe Feinstein12, and Steipler Gaon13. However, the Chasam Sofer does acknowledge that this is a chumra (stringency) and strictly speaking one may still fulfill halachic requirements by following measurements based on the size of a kezais in the place where they live. This is also quoted in the name of Rav Chaim Volozhiner14 and appears to be the position of Shach15 , Chazon Ish16, Rav Moshe Feinstein zt”l17, and Steipler Gaon18. Mishneh Berura19 assumes that one should be stringent in accordance with these opinions for mitzvos of a Torah nature, whereas one can still be lenient in this regard with certain cases involving rabbinic ordinances.
The amounts of kezais or kebeitzah are traditionally measured in terms of volume, or water displacement from a full receptacle20. The actual size suggested for a kezais varies amongst contemporary halachic authorities. The recommended measurements for the Torah level mitzvah of matzah are at least approximately 26 cubic centimeters according to Rav Chaim Noeh21, 43.2 cubic centimeters according to Rav Moshe Feinstein22, and 50 cubic centimeters according to Chazon Ish23.
It should be noted that although there are many guides that make practical recommendations as to how much matzo one must consume. However, matzos can vary in length and thickness. Therefore, these amounts should be viewed only as general approximations and one should ensure that they consume enough matzo to fulfill the basic mitzvah. For that reason, it is especially important that a Rov is consulted when minimizing the amount of matzo for someone who is ill or infirm.
Nowadays, with the absence of the Beis Hamikdash, the korban Pesach is not brought and its interdependent sister mitzvah, marror, therefore is not a Torah level precept but is currently rather a rabbinic ordinance. This is because Chazal mandated that one must still eat the traditional bitter herb independently. Therefore, while the minimal amount of marror one is required to consume at the seder is also a kezais, there are some further variances amongst halachic authorities as far as how this measurement should be calculated. The minimal size given by Rav Chaim Noeh is approximately 26 cubic centimeters , which can be limited to just a single, large leaf of romaine lettuce. Medium or small leaves of romaine lettuce will respectively amount to approximately three fifths or one fifth of the required amount. Large romaine stalks are approximately half a kezais, while small romaine stalks are roughly one quarter’s worth. A single endive is between one half to one quarter of the required amount, depending upon whether the leaf is large, medium, or small . According to this opinion, just under a filled one ounce shot glass of ground horseradish will also constitute a kezais. The measurement according to Rav Moshe Feinstein zt”l is approximately 32 cubic centimeters and 33.3 cubic centimeters according to Chazon Ish.
The requirement of drinking four cups of wine is also rabbinic in nature and the minimal measurement required for the four cups is a rivi’is for each cup. There are variances amongst contemporary halachic authorities as far as how this measurement should be calculated as well. The minimal size recommended by Rav Chaim Noeh is approximately 3 ounces , whereas 3.3 fluid ounces is the proper amount according to Rabbi Moshe Feinstein , and 5.3 fluid ounces according to Chazon Ish . It should also be noted that if one’s cup holds greater than a rivi’is, one should try to drink the entire cup or at least most of it .
1 Eruvin 4a
2 Eruvin 80b
3 Hilchos Eruvin 1:9
4 Eruvin 83a
5 Yoma 80b
6 Kerisus 14a
7 Orach Chaim 486
9 Tzlach Pesachim 116a
10 Shut Chasam Sofer O.C. 127
11 Kuntres Hashiurim 39:5, 17
12 Igros Moshe O.C. 1:136
13 Shiurin shel Torah, p. 71
14 Shaarei Rachamim, minhagei HaGr”a 165, minhagei HaGrach 51
15 Y.D. 44:12
16 Kuntres Hashiurim 39:6
17 Ibid 12
18 Shiurin shel Torah, p. 71
19 Ibid 8
20 However, see Chazon Ish Kuntres Hashiurim 39:17
21 Shiurei Torah p. 191, 193. However, 28.8 cubic centimeters is quoted as preferable. This measurement does not follow the stringency of the Tzlach. Rav Yosef Eliyahu Henkin zt’l in Teshuvos Ibra p. 45 writes that approximately half a machine matzah should meet this requirement.
22 Kol Dodi, p. 60. This assumes that largest measurement for the water displacement of an average egg is 3 fluid ounces and a kezais should therefore be half, or 1.5 fluid ounces. Since there are 28.8 cubic centimeters in a fluid ounce, the recommended amount for the mitzvah deoraisa is (28.8 × 1.5=) 43.2 cubic centimeters. This is measured at approximately a sheet of matzo that is 7” by 6.25”.
23 Shiurin shel Torah, pp. 65, 66. There are conflicting amounts quoted as to how much matzo fulfills this opinion. Shiurin shel Torah p. 66 quotes that the Chazon Ish personally assessed half a machine matzo as sufficient, whereas the Steipler Gaon suggests that two thirds of a machine matzo may actually be necessary to meet this amount. Moreover, there are contemporary seforim on halachic measurements suggesting that perhaps even more than two thirds of machine matzo would be necessary to satisfy the Chazon Ish’s opnion.