(Beraisa - R. Yehudah): One who eats the Gid ha'Nasheh of a Tamei animal is lashed twice (two sets of lashes);

R. Shimon says, he is not lashed.

Question: No matter how R. Shimon holds, he should obligate at least once!

If he holds that Isur Chal Al Isur, he should obligate lashes for eating from a Tamei animal, and for eating a Gid;

If he holds Ein Isur Chal Al Isur, he should obligate lashes for the first Isur, i.e. a Tamei animal!

If he holds that the Gid has no taste (so the Isur Tamei does not apply), he should obligate for eating a Gid!

Answer (Rava): Indeed, he holds that the Gid has no taste;

The Isur Gid does not apply, since it says "therefore Bnei Yisrael do not eat Gid ha'Nasheh." The Isur applies only when the rest of the meat is permitted.

(Rav Yehudah): If one eats Gid ha'Nasheh of a Nevelah, R. Meir obligates him twice, and Chachamim obligate him once.

Chachamim agree that for eating the Gid of an Olah or of Shor ha'Niskal (an ox sentenced to be stoned), he is lashed twice. (The Gemara will explain why.)

Question: Chachamim hold Ein Isur Chal Al Isur, even if the new Isur is Kolel (it also forbids things that were otherwise permitted, e.g. when an animal becomes Nevelah, all the meat (not just the Gid) becomes forbidden);

However, if the Kolel Isur is Chamur (more severe than the first Isur, e.g. one may not benefit from an Olah or Shor ha'Niskal), it takes effect;

Like whom is this?

Answer (Rava): It is like R. Yosi ha'Gelili;

(Mishnah): If a Tamei (person) ate Kodshim, whether the Kodshim were Tahor or Tamei, he is Chayav (Kares if he was Mezid, and Chatas if he was Shogeg);

R. Yosi ha'Gelili says, he is liable only if he ate Tahor Kodshim, but not if they were Tamei.

Chachamim: Even when he eats Tahor Kodshim, he makes them Tamei once he touches them! (How can you distinguish the cases?!)

Question: Seemingly, R. Yosi ha'Gelili is refuted!

Answer (Rava): If the person became Tamei before the Kodshim became Tamei, all agree that he is liable, for the Isur Kares (for a Tamei to eat Kodshim) came first;

They argue when the Kodshim became Tamei before the person.

Chachamim hold that since a Kolel Isur forbids things that were otherwise permitted (when he becomes Tamei, he becomes forbidden to Tahor Kodshim), it also takes effect on what was already forbidden (Tamei Kodshim);

R. Yosi ha'Gelili disagrees, for Ein Isur Chal Al Isur.

Question: Granted, R. Yosi ha'Gelili holds that Ein Isur Kolel Chal Al Isur if the old Isur is more severe. Would he say so if the new Isur is Chamur?!

For a Tamei to eat Kodshim is Chamur, since he is Chayav Kares!

Answer (Rav Ashi): He can say that the Isur to eat Tamei Kodshim is Chamur, since this can never be permitted through immersion. (A Tamei person can become Tahor, but Tamei food cannot.)

Question: Does R. Yosi ha'Gelili really hold that Ein Isur Kolel Chal Al Isur?!

(Beraisa - R. Yosi ha'Gelili): "It is Shabbos", "it is Yom Kipur" teach that if Yom Kipur falls on Shabbos and one did Melachah (b'Shogeg), he brings a Chatas for each;

R. Akiva says, he brings only one Chatas.

Answer: Ravin sent a message to Bavel that the opinions must be switched.

(Rav Yitzchak bar Yakov): According to R. Yosi ha'Gelili (after the opinions are switched), if one did Melachah, unaware that it was Shabbos but knowing that it was Yom Kipur, he is liable. If he knew that it was Shabbos but forgot that it was Yom Kipur, he is exempt.

Question: What is the reason?

Answer #1 (Abaye): Shabbos is fixed. Yom Kipur is determined by Beis Din (when they declare the new month), so it is considered to come later.

Objection (Rava): Even so, the Isurim take effect at the same moment!

Version #1 (Rashi) Answer #2 (Rava): Rav Yitzchak bar Yakov's teaching was not said about Yom Kipur that (truly) falls on Shabbos;

Rather, it refers to an episode in which Nochrim forbade keeping Yom Kipur;

Since Yisre'elim could not observe Yom Kipur, Chachamim of Eretz Yisrael enacted that people conduct on a Shabbos with the restrictions of Yom Kipur (so Yom Kipur would not be forgotten. Rav Yitzchak exempts one who did Melachah, forgetting that the day should be treated like Yom Kipur.)

Version #2 (Ramban) Answer #2 (Rava): Rav Yitzchak's teaching was mistaken.

(Ravin's message to switch the opinions was only a ruse.) Nochrim had decreed against Mitzvos;

(In Eretz Yisrael, they made Thursday Rosh Hashanah, and Yom Kipur would be on Shabbos.) To secretly inform the community in Bavel, Ravin sent the (altered) Beraisa in which R. Akiva discusses Yom Kipur falling on Shabbos (the Halachah usually follows R. Akiva. Rav Yitzchak (and Abaye) did not understand this, so he explained the Beraisa.) (end of Version #2)

Ravin, and everyone who came from Eretz Yisrael to Bavel agreed with Rava.

(Mishnah - R. Yehudah): The Gid was forbidden to Yakov's children...

(Beraisa - Chachamim): The Torah does not forbid Bnei Yakov to eat the Gid, rather, "Bnei Yisrael." They are not called Bnei Yisrael until the Torah was given at Sinai!

Rather, the Mitzvah was given at Sinai. The Torah wrote it in the appropriate place, to teach why we don't eat it.

Question (Rava): It says "Bnei Yisrael carried their father Yakov." (They are called Bnei Yisrael before Sinai!)

Answer: After Hash-m called Yakov by the name Yisrael, his children are called Bnei Yisrael.

Question (Rav Acha brei d'Rava): Chachamim should admit that after that (when they are called Bnei Yisrael), the Gid was forbidden to them!

Answer (Rav Ashi): The Torah was not given piecemeal!

Since this was not the time that the Torah was given, nor was it the time when Yakov's Gid was wounded (the source of the Mitzvah), the Mitzvah did not begin to apply then (when they were first called Bnei Yisrael).

(Beraisa - R. Yehudah and R. Elazar): The Isur of Ever Min ha'Chai (a limb of a living animal) applies to Behemos, Chayos and birds, both Tehorim and Teme'im;

Chachamim say, it applies only to Tehorim.