(Mishnah - R. Yehudah): Alal... (if a k'Zayis is gathered in one place, it has Tum'as Nevelah. Rashi - also, one who eats it is liable.)

(Rav Huna): This is only if he (the one who flayed the animal) gathered them.

(Rav Huna): If two pieces of meat are on the skin, and each is half a k'Zayis, the skin is Mevatel them. (They are not like Nevelah.)

Question: According to which Tana (in the Mishnah 124a) is this teaching?

It is unlike R. Yishmael. He holds that the skin is not Mevatel the meat!

It cannot be like R. Akiva. He explicitly says that the skin is Mevatel the meat! (Surely, Rav Huna did not merely teach the Mishnah. If he wanted to teach that the Halachah follows R. Akiva, he should have explicitly said so.)

Answer #1: Really, he holds like R. Yishmael;

R. Yishmael admits that the skin is Mevatel meat that comes off the knife when flaying the animal (since he leaves the meat there). That Mishnah discusses when a Chayah bit the animal, and some meat stuck to the skin. No person was Mevatel it.

Objection (Mishnah - R. Yehudah): If a k'Zayis of Alal is gathered in one place, one is liable for it.

(Rav Huna): This is only if he (the flayer) gathered it.

Granted, if R. Yishmael holds that skin does not Mevatel meat, even if the meat came off a knife, then Rav Huna explains R. Yehudah like R. Yishmael;

Summation of objection: However, if R. Yishmael admits (to R. Akiva) that skin is Mevatel meat that comes off a knife, R. Yehudah is not like either of these two Tana'im! (They hold that it is Batel. Even if he gathers it, it is not Nevelah.)

Answer #2: Really, Rav Huna holds like R. Akiva.

Question: If so, what is his Chidush?

Answer: One might have thought that R. Akiva said that skin is Mevatel meat only if it came off a knife;

Rav Huna teaches that R. Akiva says this even if it came from a Chayah's bite.

We learn this from R. Akiva's words. He attributes the Bitul to the skin.

(Mishnah): The following skins are (Tamei) like the flesh:

Skin of man, domestic pigs, the hump of tender (young) camels, and the head of tender calves;

Regarding all animals, skin of the feet, womb, a fetus, and under the tail;

Skin of an Anakah (a porcupine, hedgehog or beaver?), praying mantis, lizard, and a slug.

R. Yehudah includes also (the skin of) a wild pig, but excludes a lizard, for it is like a rat. (Its skin is not Tamei.)

Regarding all non-human skins, if it was tanned or trampled enough for tanning, it is Tahor.

R. Yochanan ben Nuri says, the skin of all eight Tamei Sheratzim is Tahor.

Version #1 (Gemara - Ula): Mid'Oraisa, human skin is Tahor. Chachamim decreed that is Tamei, lest people make mats from their parents' skin.

Version #2 (Mishnah): Regarding all non-human skins, if it was tanned or trampled enough for tanning, it is Tahor.

(Ula): Mid'Oraisa, tanned human skin is Tahor. Chachamim decreed that it is Tamei lest people make mats from their parents' skin.

According to Version #1, Ula surely agrees that tanned human skin is Tamei only mid'Rabanan.

According to Version #2, Ula holds that untanned human skin is Tamei mid'Oraisa.

(Mishnah): The skin of domestic pigs...

Question: What do they argue about?

Answer: R. Yehudah includes skin of a wild pig because he he holds that it is soft. The first Tana holds that it is hard.

(Mishnah): The hump of a tender camel...

Question: How long is it considered tender?

Answer (Ula citing R. Yehoshua ben Levi): It is tender as long as it has not borne a burden.

Question #1 (R. Yirmeyah): If it is old enough to bear a burden, but it has not done so, what is the law?

Question #2 (Abaye): If it is not old enough to bear a burden, but it did, what is the law?

These questions are unresolved.

Reish Lakish did not know how long is it considered tender. R. Yishmael bar Aba cited R. Yehoshua ben Levi's answer. Reish Lakish showed his gratitude.

R. Zeira did not know how long is it considered tender. Ravin bar Chinena cited the above answer. He did not think that R. Zeira heard him, so he repeated it. R. Zeira scolded him for trying to show off his knowledge.

This shows the difference between great people of Eretz Yisrael (Reish Lakish) and the most pious of Bavel (R. Zeira).

(Mishnah): The head of a tender calf...

Question: How long is it considered tender?

Answer #1 (Ula): It is tender for one year.

Answer #2 (R. Yochanan): It is tender as long as it is nursing.

Question: Did Ula mean that it is one year provided that it is nursing, and R. Yochanan said that it is as long as it is nursing (even past a year);

Or, did Ula mean that it is one year even if it ceased nursing, and R. Yochanan said that it is one year only if it is still nursing?

Answer: R. Yochanan said "as long as it is nursing" (he increases the time), not "provided that it is nursing" (to diminish the time).

Question (Reish Lakish): Is the skin of the head of a tender calf Metamei?

Answer (R. Yochanan): It is not.

Question (Reish Lakish): You taught to us the Mishnah that the skin of the head of a tender calf is like the flesh!

Answer (R. Yochanan): The Mishnah is like an individual. The Halachah follows Chachamim;

(Beraisa): If an Olah was slaughtered with intention to burn in the wrong place (i.e. not on the outer Mizbe'ach) the skin under the tail, the Korban is Pasul, but one who eats it is not Chayav Kares;

If he intended to burn it after the allotted time (that day), the Korban is Pigul, and one who eats it is Chayav Kares.

Eliezer ben Yehudah says, Pasul and Pigul apply also to (improper intent to eat or burn) skin of the feet, skin of a tender calf's head, and skins that are Tamei like the flesh;

This comes to include skin of the womb in a female Korban.

(The first Tana does not include the head of a tender calf, because he holds that it is not like the flesh.)

(Mishnah): Skin of the feet.

Question: What is considered skin of the feet?

Answer #1 (Rav): It includes only the skin of the feet (up to the ankle).

Answer #2 (R. Chanina): It includes all the skin up to the (lower) knee.

(Mishnah): The skin of an Anakah...

(Beraisa): "Ha'Teme'im" includes the skins (of Sheratzim. They are Tamei like the flesh.)

Suggestion: Perhaps this applies to all eight Sheratzim listed!

Rejection: (It applies only to) "Eleh".

Question: "Eleh" refers to all of them!

Answer (Rav): "L'Minehu (and others in this species)" separates. ("Eleh" refers only to what is written after "l'Minehu".)

Question: If so, the Mishnah should list also a mole, for also this is after "l'Mineihu"!

Answer (R. Shimon bar Yitzchak): Rav is considered a Tana. He argues with the Mishnah and includes a mole.

Question: Why do Chachamim (the first Tana) argue?

Answer: They hold like R. Yehudah, who judges based on the feel of the skin (Rashi - to decide which skins are like the flesh; Tosfos - to decide to which skins "ha'Teme'im" refers).

They argue with R. Yehudah about a lizard. (Chachamim hold that its skin is like flesh.)

(Mishnah): Any skins that were tanned...

Inference: They are Tahor only if they were trampled on.

Question (Beraisa - R. Chiya): If a donkey's ear was used to patch a box, it is Tahor. (Rashi - similarly, placing skins where they will be trampled should suffice to be Metaher them! Tosfos - if our Tana agreed to this, he should have taught this case. It is a bigger Chidush!)

Answer: An ear need not be trampled to patch a box. For other uses, trampling is required. (Tosfos - both Chidushim are equal.)

Question: What is considered "trampled enough for tanning"?

Answer (Rav Huna): It is the time to walk four Mil (one Mil is 2000 Amos).

(R. Avahu citing Reish Lakish): Four Mil is the Shi'ur for the following:

Kneading (Rashi - One who was hired to knead a dough b'Taharah must walk four Mil to immerse Kelim (without extra compensation); Tosfos - one who wants to hire someone to knead his dough should walk four Mil to get someone who will do this b'Taharah);

Prayer (one must walk four Mil in order to pray with a Tzibur - Rashi;Tosfos - in order to immerse from Tum'as Keri before praying);

Washing the hands (one must walk four Mil in order to get water to wash before eating).

(Rav Nachman bar Yitzchak): Eibo said this, and not R. Avahu. He included a fourth case, trampling skins (in our Mishnah).