THINGS THAT ARE NEVER BATEL
(Mishnah): Similarly, if a piece of Nevelah (was cooked with permitted pieces... if we cannot recognize the Isur, all are forbidden).
Question: It should be Batel in the majority! (A Mishnah teaches about important things that are never Batel. Amora'im argue about the text of the Mishnah.)
This is not difficult according to the text 'Kol (everything) that it is normal to count' (is important and is never Batel. It is normal to count pieces of Nevelah);
However, according to the text 'Es (only) what is (always) counted', the piece should be Batel!
Answer: A Chatichah ha'Reuyah Lehiskaved (a piece proper to honor guests with) is important, so it is never Batel.
The Mishnah must teach both cases;
Had it taught only that a Gid is never Batel, one might have thought that this is because it is a Briyah, but a piece can become Batel;
Had it taught only that a piece of Nevelah is never Batel, one might have thought that this is because it is proper to honor guests, but a Gid can become Batel.
A PIECE BECOMES LIKE A NEVELAH
(Rabah bar bar Chanah): If a piece of Nevelah or of a Tamei fish fell into a pot, it forbids the contents only if the piece is big enough to give taste to the liquid, sediments, and pieces of meat in the pot.
(Rav): Once the Nevelah gives taste to another piece, that piece is itself like a Nevelah, and it forbids all the pieces, for they are the same Min.
Question (Rav Safra): Rav's law is like R. Yehudah, who holds that Min b'Mino is never Batel. Even if the Nevelah didn't give Ta'am to another piece, it would forbid them all!
Answer #1 (Abaye): The case is, the Nevelah was removed from the pot before (some of) the other pieces were put in. They did not absorb from it at all.
Answer #2 (Rava): We can explain even when the Nevelah was not removed from the pot;
Since the Nevelah is mixed with Mino (pieces of meat) and Eino Mino (the liquid and sediments), we ignore Mino, and Eino Mino (if there is enough) is Mevatel the Nevelah.
IS THE GID OF A TAMEI ANIMAL FORBIDDEN?
(Mishnah): The prohibition of Gid ha'Nasheh applies to Tahor animals, not to Tamei animals;
R. Yehudah says, it also applies to Tamei animals.
R. Yehudah: It was forbidden from the time of Yakov's children, and Tamei animals were permitted then!
Chachamim: It became forbidden only when the Torah was given at Sinai. It was written in the appropriate place.
(Gemara) Question: Does R. Yehudah really hold that Isur Chal Al Isur (a prohibition takes effect even on something that is already forbidden?!)
(Beraisa - R. Yehudah) Suggestion: If one eats Nivlas Ohf Tamei, perhaps (he and) his clothes become Tamei!
Rejection: "He will not become Tamei by eating a Nevelah or Terefah" - the Tum'ah of eating applies only to birds forbidden due to Nevelah;
It does not apply to Tamei birds, which are not forbidden due to Nevelah, rather, because they are Tamei. (I.e. the Isur of Nevelah is not Chal on the Isur Tamei.)
Suggestion: Perhaps R. Yehudah holds that the Gid ha'Nasheh has no taste (so the Isur of Tamei animals does not apply to it, therefore the Isur Gid is Chal)!
Rejection: R. Yehudah holds that the Gid has taste!
(Beraisa - R. Yehudah): One who eats the Gid of a Tamei animal gets two sets of lashes;
R. Shimon says, he is not lashed.
Answer #1: Really, R. Yehudah holds that the Gid has taste. He holds that the Gid of a fetus is forbidden, therefore, the Isurim of Gid and Tamei come simultaneously, so both take effect.
Question: Does R. Yehudah really forbid the Gid of a fetus?!
(Mishnah): The Isur of Gid applies to a fetus;
R. Yehudah says, it does not;
The Chelev of a fetus is permitted.
Answer: R. Yehudah permits the Gid of a fetus only of a Tahor animal, about which it says "all that is in the animal you may eat", but the Gid of a Tamei fetus is forbidden.
Objection: The Isurim do not come simultaneously!
(Mishnah): If a Nazir became Tamei through any of the following, he must be Megale'ach (shave, and bring Korbanos and start Nezirus again): a Mes (corpse), a k'Zayis of a Mes...
Question: If he shaves for a k'Zayis of a Mes, there is no need to teach for a (full) Mes!
Answer (R. Yochanan): The Chidush of a (full) Mes applies to a Nefel (miscarriage) whose limbs were not yet bound with Gidim (and it is less than a k'Zayis. Just like a human fetus is Metamei even before it has Gidim, a fetus of a Tamei animal is forbidden before it has Gidim)!
Answer #2: Indeed, the Isur Gid comes after the Isur Tamei. It takes effect anyway, because the Gid was forbidden to Bnei No'ach (i.e. it is a more severe Isur than Tamei);
Support (Mishnah - R. Yehudah): The Gid was forbidden from the time of Yakov's children, and Tamei animals were permitted to them!