Sunday, September 21, 2008

Bavli vs. Yerushalmi on chatzi shiur

The gemara asks why the Mishna at the end of Yoma refers to eating on Yom Kippur as being "assur" and not "chayav", as one who eats on Y"K is chayav kareis. The gemara explains that the Mishna is dealing with a case where one ate a chatzi shiur which, according to Reish Lakish, is only an issur derabbanan but not a chiyuv kareis.

What is amazing is that the Yerushalmi at the beginning of the 6th perek of Terumos presents Reish Lakish as holding exactly the opposite view. According to the Yerushalmi, although Reish Lakish in other areas holds that chatzi shiur is only an issur derabbanan, davka by Yom Kippur he agrees with R' Yochanan that chatzi shiur is an issur d'oraysa.

The reasoning of the Yerushalmi actually seems to be as follows: When the Torah uses the term "achila" it implies a minimum shiur of a k'zayis. However, the Torah never uses the terms "achila" with respect to the prohibition of eating on Y"K -- it uses the term "inuy". Even eating the smallest amount of food diminishes the feeling of inuy.

What are we to make of these two versions of Reish Lakish completely at odds with with each other? The Tziyun Yerushalayim on the Yerushalmi quotes R' Ya'akov Emden as offering a creative way to reconcile the two. According to the Mishna, the chiyuv kareis for eating on Yom Kippur applies only if the amount of a k'koseves hagasah, a large date (larger than a k'zayis), is eaten. R' Y"E suggests that perhaps there are actually two levels of chatzi shiur. If less than a k'zayis was eaten on Y"K, both the Bavli and Yerushalmi agree that Reish Lakish would hold that the issur is only derabbanan -- since this amount does not constitute what the Torah usually calls achila, there is no Biblical chiyuv. The Yerushalmi Terumos is adding an additional chiddush that applies only where one ate more than a k'zayis on Yom Kippur but less than a k'koseves hagasah, i.e. less than the amount that would generate a chiyuv kareis. Although technically this achila can also be called a chatzi shiur with respect to Yom Kippur, since this achila surpasses the normal threshold for what constitutes achila in other areas, even Reish Lakish would hold it is Biblically prohibited on Yom Kippur as well.


  1. Anonymous12:01 PM

    Let me remind you of a shakla vetaria we had last August: I wrote

    "The Knesses Hagdola’s shittah, which is also the shitta of the Pri Megodim brought in the Mishneh Berura 210, is that an achila of a kezayis in more than an achilas prass is mitztaref and is mechayev bentching midoraiso– but only if he is sovai’a. On the other hand, it seems to me that if one would do so on Yom Kippur, he would not be chayov koreis. So, strangely enough, if one would eat a kezayis of bread on Yom Kippur but not toch kedei achilas peras, and he was sovei’a, he would be pottur as far as Yom Kippur, but he would have to bentch mide’orayso. Anything can happen on Torah Avenue."

    You responded

    "You probably already saw the Minchas Chinuch who assumes you need a ma'aseh achila=k'zayis within achilas pras, and seviya on top of that (he is mesupak if the shiur seviya can occur after the shiur of k'dei achilas pras). With regards to Y"K, the geder haissur is inuy, not achila. On erev Y"K there is the chumra of eating raisins or sucking candy all day - even though this does not constitute achila on the d'oraysa level, the mitzva of erev Y"K is the opposite of inuy and has nothing to do with shiurim in achila."

  2. Anonymous12:12 PM

    I forgot to say thank you for the interesting machlokes B and Y. I'll add it to the shitta about chatzi shiur in daled amos on Shabbos.