RAVA'S SOURCE
Rava: I learn from a Beraisa;
(Beraisa): The following receive Tum'as Ochlim, even though they are Isurei Hana'ah:
Orlah, Kilai ha'Kerem, Shor ha'Niskal (an ox sentenced to be stoned), Eglah Arufah, Tziporei Metzora (he brings birds to permit him to enter the city), Peter Chamor, and Basar v'Chalav.
R. Shimon says they do not receive Tum'as Ochlim, except for Basar v'Chalav, for it had Sha'as ha'Kosher (it was once permitted to Yisrael, when they were first mixed together, before they were cooked together).
(Rav Asi): R. Shimon learns from "mi'Kol ha'Ochel Asher Ye'achel" - something is considered food (regarding Tum'as Ochlim) only if one may feed it to others (Nochrim. I.e., one may benefit from it, even if a Yisrael may not eat it).
Question: Why is R. Shimon Metamei Basar v'Chalav due to She'as ha'Kosher? It suffices that one may feed it to others!
(Beraisa - R. Shimon ben Yehudah citing R. Shimon): One may not eat Basar v'Chalav, but one may benefit from it. It says "Ki Am Kodesh Atah (... Lo Sevashel Gedi ba'Chalev Imo)," similar to "v'Anshei Kodesh Tiheyun Li (u'Vasar ba'Sadeh Terefah Lo Sochelu)";
Just like one may benefit from a Terefah but not eat it, the same applies to Basar v'Chalav.
Answer: R. Shimon gives a second reason to be Metamei Basar v'Chalav;
Firstly, it is Tamei because one may feed it to others (he permits benefit from it). Secondly, it was once permitted to Yisrael.
Summation of Rava's source: If R. Shimon permits benefit from Peter Chamor after Arifah, he should agree that it is Mekabel Tum'as Ochlim!
Rejection: If one intended to eat it, indeed R. Shimon would agree;
R. Shimon is Metaher when there was no intent to eat it.
Question: If there was no intent, why are Chachamim Metamei?
Answer #1 (Rabanan): Isuro Chishuvo (the Torah forbids it, this shows that it is considered food)!
Question (Rav Sheshes): Do Chachamim really hold that Isuro Chishuvo?
(Mishnah): There are 13 laws of Nivlas Ohf Tahor (the Nevelah of a Tahor bird). One is, it requires intent (to eat it in order to receive Tum'as Ochlim, for normally people do not eat it);
(Because it has a severe Tum'ah, i.e. it is Metamei one who eats it,) it does not require Hechsher for Tum'as Ochlim. (It is Mekabel Tum'ah even if no liquid was put on it. Some explain that it has Tum'as Ochlim even without touching Tum'ah.)
If Isuro Chishuvo, it should receive Tum'as Ochlim without intent!
Answer: That Mishnah is like R. Shimon. (He does not hold that Isuro Chishuvo.)
Question (Mishnah): The following require intent, but they do not require Hechsher:
The Nevelah of a Tamei (species of) animal, in any place;
Nivlas Ohf Tahor and Chelev in villages.
If Isuro Chishuvo, they should not require intent!
Answer: Also that Mishnah is also like R. Shimon.
Question (Mishnah): The following do not require intent (because some people eat them) nor Hechsher;
The Nevelah of a Tahor animal, in any place;
Nivlas Ohf Tahor and Chelev in markets.
Inference: Nevelah of a Tamei animal requires intent!
Suggestion: Perhaps also this is like R. Shimon.
Rejection: Since the Seifa is like R. Shimon, the Reisha is not R. Shimon!
(Seifa - R. Shimon): Also a camel, hare and hyrax and pig do not need intent nor Hechsher.
(Beraisa - R. Shimon): This is because each has one Siman of Kashrus.
Answer #2 (to Question (c) - Rava): No one holds that Isuro Chishuvo;
If Arifah was done, all agree that it is Tahor;
They argue about Shechitah for the sake of practicing, like Nimus and R. Eliezer.
(Beraisa - Nimus): If one slaughtered a raven to practice, its blood is Machshir;
R. Eliezer says, blood of Shechitah is always Machshir.
Question: This is like Nimus!
Answer #1: They argue about whether Isuro Chishuvo;
Nimus says that its blood is Machshir other food, but the raven itself is not Huchshar without intent. R. Eliezer says that blood of Shechitah is always Machshir. Even the raven is Huchshar without intent.
Rejection: Perhaps R. Eliezer is Machshir because a raven has (two) Simanei Taharah! (There are four Simanim of Tamei birds, i.e. similarities to a Nesher (eagle; see Mafteach Hatorah to Mishlei 30:17:3:1**). Every other Tamei species has at most three Simanei Tum’ah, and at least one Siman Taharah.)
Question: What is the source that Simanei Taharah affect Hechsher?
Answer: (Beraisa - R. Shimon): (The camel, hare... do not need intent nor Hechsher;) this is because each has one Siman of Kashrus.
Question: If R. Eliezer is Machshir due to Simanei Taharah, why does the Beraisa discuss Shechitah for practice? He should be Machshir even Mis'asek! (He was not intending to slaughter, and he slaughtered!)
Answer: Indeed, he is Machshir even Mis'asek. The Beraisa discusses Shechitah for practice to teach the extremity of R. Nimus. Even though he intended to slaughter, it is not Machshir the bird.
Question (Beraisa - R. Yehudah): If he did not want to give a Seh to a Kohen, he breaks its neck from the back with a Kopitz (chopping knife) and buries it. It is Asur b'Hana'ah;
R. Shimon permits benefit from it.
Answer: This means that R. Yehudah forbids benefit mi'Chayim (while it is alive), and R. Shimon permits.
Question: Since the Seifa discusses mi'Chayim, the Reisha does not discuss mi'Chayim!
(Seifa - R. Yehudah): He may not kill it with a reed, scythe, axe, or saw. He may not lock it in a room to die. One may not shear it or work with it;
R. Shimon permits.
Answer: The entire Beraisa discusses benefit mi'Chayim. The Reisha discusses benefit from its value (e.g. to rent it), the Seifa discusses benefit from it itself;
It must teach both cases;
Had it taught only about benefit from its value, one might have thought that R. Shimon permits this, but forbids benefit from it itself;
Had it taught only about benefit from it itself, one might have thought that R. Yehudah forbids this, but permits benefit from its value.
RAV NACHMAN'S TEACHING
Version #1: Also Rav Nachman taught that R. Shimon agrees that Peter Chamor is Asur b'Hana'ah after Arifah.
Support (Rav Nachman for himself - Beraisa): It says "va'Arafto" regarding Peter Chamor, like it says regarding Eglah Arufah;
Just like there it is Asur b'Hana'ah (after Arifah), also here.
Question: Who is the Tana of the Beraisa?
It cannot be R. Yehudah. He forbids benefit even mi'Chayim!
Answer #1: It is R. Shimon.
Rejection (and Answer #2 - Rav Safra): Really, the Beraisa is R. Yehudah;
One might have thought that Arifah is in place of redemption. Just like it is permitted after redemption, also after Arifah;
The Beraisa teaches that this is not so.
Support (Rav Nachman for himself - Levi - Beraisa): Because the Yisrael deprived the Kohen (he refused to give a Seh), the Torah deprives him of his money (commands him to kill the Peter Chamor).
Question: Who is the Tana of the Beraisa?
It cannot be R. Yehudah. He forbids benefit even mi'Chayim (Arifah does not deprive the Yisrael. He was already deprived!)
Answer #1: It is R. Shimon.
Rejection: The Beraisa can be like either Tana. In any case it does not support Rav Nachman;
It can be like R. Yehudah. (The Yisrael could have redeemed the Peter Chamor for a Seh worth less than it, so) Arifah deprives him of the difference;
It can be like R. Shimon, and yet he may benefit from it after Arifah. Arifah deprives him of the difference in value (of a live donkey from a dead one).
(Reish Lakish): R. Shimon agrees that Peter Chamor is Asur b'Hana'ah after Arifah;
(R. Yochanan): He argues (and permits) also after Arifah.
Version #2A - (Mishnah): If Reuven was Mekadesh Leah with a Peter Chamor, she is not Mekudeshes.
Suggestion: This is like R. Yehudah. According to R. Shimon, one may benefit from a Peter Chamor, so she would be Mekudeshes!
Rejection (Rav Nachman): The Chamor was given after Arifah. The Mishnah is even like R. Shimon.
Version #2B - Question: The Mishnah is not like R. Yehudah, nor like R. Shimon!
It is not like R. Shimon. He permits benefit from a Peter Chamor. She would be Mekudeshes!
It is not like R. Yehudah. He holds that she would be Mekudeshes with the net value she received, i.e. the value of the donkey less the cost (of a Seh) to redeem it!
Answer (Rabah bar Avuha): It is like R. Yehudah. The case is, the Peter Chamor is worth only one Shekel. (It has no net value, for) R. Yehudah holds like his son;
(Beraisa): It says "Tifdeh" twice teaches that a Peter Chamor may be redeemed immediately, and it may be redeemed for (a Seh worth) any amount;
R. Yosi bar Yehudah says, the (Seh for) redemption must be (worth) at least one Shekel.
Question: The first Tana learns that it may be redeemed immediately and for (a Seh worth) any amount because it says "Tifdeh" twice. This is obvious! (Why would we think otherwise?)
Answer: Peter Chamor is equated to Bechor Adam;
One might have thought that just like Bechor Adam cannot be redeemed until 30 days, and it must be redeemed for five Shekalim, the same applies to Peter Chamor. "Tifdeh" and "Tifdeh" teach that this is not so.
(Beraisa - R. Yosi bar Yehudah): The redemption must be at least one Shekel.
Question: In any case, this is difficult!
If R. Yosi equates Peter Chamor to Bechor Adam, he should require five Shekalim;
If he does not equate them, why does he require a Shekel?
Answer (Rava): Really, he does not equate them;
"V'Chol Erkecha Yihyeh b'Shekel ha'Kodesh" teaches that every Erech (for our purposes, redemption) must be at least one Shekel.
Chachamim disagree. They say that the verse teaches about Heseg Yad. (If a poor person pledged to give an Erech and cannot afford it, he pays what he can afford, but it must be at least one Shekel.)