brought to you by Kollel Iyun Hadaf of Yerushalayim
& Revach l'Neshamah - http://www.revach.net
1. There is a dispute about whether the prohibition against eating Neveilah is transgressed if the amount is a combination of Kosher and non-Kosher animal.
2. It is unclear what Rav Asi means when he says that Neveilah of Kosher and non-Kosher animals "are separate."
3. In contrast to Levi, both Rav Asi and Rav maintain that "Ein Isur Chal Al Isur."
4. Rav: One who eats a k'Zayis of a live Sheretz transgresses the prohibition against eating Sheratzim.
5. Rebbi Yosi and Rebbi Yochanan: One who eats an amount the size of an Adashah (lentil) of a dead Sheretz transgresses the prohibition against eating Sheratzim.
A BIT MORE
1. Rav: The Mishnah only means that the amounts combine to form the impurity of Neveilah, not to transgress the prohibition of eating Neveilah. Levi: They also combine for the prohibition of eating Neveilah.
2. Some consider this to be a third opinion (see #1). That is, Neveilos of Kosher animals combine, and Neveilos of non-Kosher animals combine separately. Others say that Rav Asi agrees with Rav that Kosher and non-Kosher animals do not combine to make a Shi'ur for the prohibition against eating Neveilah.
3. Accordingly, Rav and Rav Asi understand that the prohibition of Neveilah does not apply to a non-Kosher animal, since it was already forbidden when it was alive (because it is a non-Kosher species of animal). Therefore, they maintain that it cannot combine with a Kosher animal to form the amount for which one is liable.
4. Rav understands that one must eat an amount of a k'Zayis to transgress this prohibition, because the Torah expresses the prohibition with the term of "eating" ("Do not eat them"). "Eating" always refers to a k'Zayis.
5. Rebbi Yosi derives this from a verse that discusses the Tum'ah of a Sheretz (which applies only to dead Sheratzim) and the prohibition against eating a Sheretz. The verse compares the amount required for transgressing the prohibition against eating to the amount required for Tum'ah, which is an Adashah.
Next Daf Index to Revach for Maseches Me'ilah