Monday, March 27, 2006

Chatzi shiur by chameitz

The Rambam writes (1:7) that even a "kol she'hu" of chameitz is prohibited because of the pasuk "lo ye'achel chamietz". The achronim all ask: achila in the Torah always means a k'zayis. There is a machlokes R' Yochanan and Reish Lakish (Yoma 85) whether less than the shiur of k'zayis (a "chatzi shiur") is assur min haTorah or only m'derabbanan, based either on a limud from a pasuk by cheilev or because of a sevara that each chatzi shiur is "chazi l'itztarufei", it can potentially combine with another chatzi to become a complete shiur. So here we have the Rambam (1) using the pasuk "lo ye'achel", with the term achila which means k'zayis, to prove the halacha of chatzi shiur; and (2) citing a makor for chatzi shiur that is unique to chameitz and distinct from the sugya in Yoma.
I unfortunately am pressed for time, so I will just be m'orer the difficulty for now. Maybe at some other point I can offer more.


  1. Josh Fruchter2:17 AM

    This is a question of the kesef mishnah. I am told the nodah b'yehudah in yoma (74a) addresses this question. As you note, the sevara why chatzi shiur is asur is chazi l'atztrufei. But because chametz is a time-bound issur, what if someone eats a chatzi shiur of chametz at the very end of shevi'i shel pesach when there is no opportunity for eating additional quantities before Pesach is over. If the sevara of chatzi shiur is chazi l'atztrufei, then would seem okay to eat a chatzi shiur of chametz at the end of pesach since, b'metzius, the individual will not have time eat a kezayis - i.e., the eating will not combine into a full shiur. So Rambam offers a pasuk to teach that, even so, a chatzi shiur of chametz is still assur at any point during Pesach, even in such a circumstance. of course, there are other ways to explain chatzi shiur, but perhaps this was the Rambam's understanding.