(R. Yosi b'Rebbi Chanina): R. Eliezer and R. Yehoshua argue about when Terumah falls into less than 100 times its own volume of Tamei Chulin - but if there is at least 100 times as much, all agree that one may not Metamei it [because the mixture will be permitted].

Support (Beraisa): If a barrel of Terumah broke in the upper winepress and it is about to fall into 100 times its own volume of Tamei Chulin below, R. Eliezer agrees to R. Yehoshua that if one can save a Revi'is in Taharah, he must do so; and if he cannot, he must allow the Terumah to fall, he may not actively Metamei it.

Question: Why does it say that R. Eliezer agrees to R. Yehoshua - it should say that R. Yehoshua [who permits to actively Metamei] agrees to R. Eliezer [who forbids this]!

Answer #1 (Rava): The Beraisa must be switched to say that R. Yehoshua agrees to R. Eliezer.

Answer #2 (Rav Huna brei d'Rav Yehoshua): We need not switch it - [it refers to saving a Revi'is in Taharah;] the case is, the inside of the Kli is Tahor and the outside is Tamei;

One might have thought that R. Eliezer [who does not allow to overtly Metamei] would forbid saving, lest Terumah touch the outside and become Tamei - the Beraisa teaches that this is not so, he agrees that one [may and] must save.

(Mishnah): As long as it is permitted to eat [Chametz on Erev Pesach], one may feed it to Behemos and Chayos (domestic and wild animals) and birds or sell it to a Nochri; one may benefit from it;

After the [permitted] time expires, it is Asur b'Hana'ah; one may not use (burn) it to heat an oven;

R. Yehudah says, the only way to fulfill Bi'ur is through burning;

Chachamim say, one may even crumble it and cast it into the wind or the sea.

(Gemara) Inference: As long as it is permitted to eat, one may feed [animals] - once it is forbidden to eat, one may not feed.

Suggestion: Our Mishnah is unlike R. Yehudah - he forbids eating in the fifth hour but permits feeding!

(Mishnah - R. Meir): One may eat Chametz until the end of the fifth hour; we burn it at the beginning of the sixth hour;

R. Yehudah says, one may eat until the end of four hours; we Toleh during the fifth hour, and we burn at the beginning of the sixth hour.

Objection: It is also unlike R. Meir!

Why does it say 'As long as it is permitted to eat' [connoting that some people are permitted and others are forbidden] - it should say 'as long as one may eat' (R. Meir holds that there is one time limit [for eating] for everyone)!

Answer (Rabah bar Ula): Indeed, our Mishnah is R. Gamliel:

(Mishnah - R. Gamliel): Chulin may be eaten until the end of the fourth hour; Terumah may be eaten until the end of the fifth hour; we burn at the beginning of the sixth hour.

Our Mishnah means, as long as Kohanim may eat Terumah (five hours), a Yisrael may feed Chulin to animals.

Question: Why does the Mishnah specify Behemos and Chayos?

Answer: It must teach both of them:

Had it taught only Behemos, we would think that one may feed them because one will see what they leave over [and destroy it] - but Chayos hide their leftovers, we would not permit feeding them;

Had it taught only Chayos, we would think that one may feed them because they hide their leftovers, one will not transgress Bal Yera'eh (Tosfos - unless he sees it; Rashi, according to Maharshal - even though he transgresses Bal Yimatzei even without seeing it), but we would not permit feeding Behemos, lest they leave over and he will forget to Mevatel, and he will transgress Bal Yera'eh and Bal Yimatzei.

Question: Why does the Mishnah need to permit birds?

Answer: Once it says Behemos and Chayos, it also says birds.

(Mishnah): Or sell it to a Nochri.

Objection: This is obvious!

Answer: The Mishnah teaches unlike the following Tana:

(Beraisa - Beis Shamai): One may not sell Chametz to a Nochri unless he knows that the Nochri will finish it before Pesach;

Beis Hillel permit selling Chametz as long as it is permitted to eat it;

R. Yehudah says, all kinds of Kutach (dips made with Chametz; they are consumed very slowly) may not be sold 30 days before Pesach.

(Mishnah): One may benefit from it.

Objection: This is obvious (we already permitted feeding animals and selling it to Nochrim)!

Answer: The Mishnah discusses Chametz that was charred before [the time of Isur] - it permits benefit even after Chametz is forbidden [for this is not considered Chametz].

(Mishnah): After the [permitted] time expires, it is Asur b'Hana'ah.

Objection: This is obvious!

Answer: The Chidush is, it becomes Asur b'Hana'ah mid'Rabanan [while it is still permitted mid'Oraisa]:

(Rav Gidal): If one was Mekadesh with wheat of Kordenisa from (Rashi - the start of; Tosfos - the end of) the sixth hour or later, we are not concerned for the Kidushin. (Rashi - the wheat is forbidden mid'Rabanan, so it is worthless. Tosfos - just like Chachamim said that Chametz mid'Rabanan is Asur b'Hana'ah at a time when real Chametz is Asur mid'Oraisa, they said that Chametz mid'Oraisa is Asur b'Hana'ah at a time when real Chametz is Asur mid'Rabanan.)

(Mishnah): One may not use it to heat an oven.

Objection: This is obvious!

Answer: This is a Chidush according to R. Yehudah:

R. Yehudah says that the only way to fulfill Bi'ur is through burning - [since it is a Mitzvah,] one might have thought that one may benefit from it at the time - the Mishnah teaches that this is not so.

(Chizkiyah) Question: What is the source that Chametz during Pesach is Asur b'Hana'ah?

Answer: "V'Lo Ye'achel Chametz" (passive, it will not be eaten) - you have no permission to eat it [or benefit from it, since the savings or what is exchanged for it can be consumed; Rashash - it may not be eaten, even by a dog - other benefit is likewise forbidden].

Inference: Had it not said Ye'achel, we would have said that one may not eat it but one may benefit from it - this is unlike R. Avahu.

(R. Avahu): Wherever the Torah says "Lo Yochal" [or "Lo Ye'achel"], "Lo Sochal," or "Lo Sochlu," it forbids eating and benefit, unless there is a source to permit benefit, like we find by Neveilah;

(Beraisa - R. Meir) Question: "Lo Sochlu Chol Neveilah la'Ger Asher bi'Sh'arecha Titnenah va'Achalah O Machor l'Nochri" only permits giving [a Neveilah for free] to a Ger (Toshav, i.e. a Ben Noach who accepted to observe his Mitzvos) and selling it to a Nochri (idolater).

What is the source to permit selling it to a Ger?

Answer: "La'Ger... Titnenah...O Machor."

Question: What is the source to permit giving it to a Nochri?

Answer: "Titnenah va'Achalah O Machor l'Nochri."

Conclusion: It may be given or sold to a Ger or Nochri.

R. Yehudah says, it is permitted only like the Torah says, a gift to a Ger or a sale to a Nochri.

Question: What is R. Yehudah's reason?

Answer: If the Torah meant like R. Meir, it should have said 'La'Ger... Titnenah...u'Machor';

Rather, it says "O Machor" to teach that one may do only like the Torah said. (see note 15 in Appendix)

Answer: "Titnenah va'Achalah O Machor l'Nochri."

Conclusion: It may be given or sold to a Ger or Nochri.

R. Meir says, "O" teaches that it is better to give it to a Ger than to sell it to a Nochri.

R. Yehudah says, since we are commanded to support a Ger but not a Nochri, we already know that a gift to a Ger is better.

Question (against R. Avahu): According to R. Meir who permits giving and selling to a Ger or Nochri, we understand [the source that Isurei Achilah are Asur b'Hana'ah] - the verse permits benefit from a Neveilah, implying that normally one may not benefit from something forbidden to eat;

But according to R. Yehudah, the verse specifies what is permitted (a gift to a Ger or a sale to a Nochri) - what is the source that normally, Isurei Achilah are Asur b'Hana'ah?