Question: In Pesachim (24b), Isi bar Yehudah expounds Isur Achilah from here, and he learns Isur Hana'ah from a Kal v'Chomer from Orlah. What do they argue about?

Answer #1: The Tana there holds that since one can fulfill both of them, the Gezeirah Shavah and the Kal v'Chomer, he fulfills [both of] them.

Question: In several places a Gezeirah Shavah uproots a Kal v'Chomer, like it says in several places "perhaps..." and it makes a Kal v'Chomer, and responds "it says [...] for a Gezeirah Shavah." This shows that a Gezeirah Shavah uproots a Kal v'Chomer!

Answer #2 (R. Tam): The verse discusses something Asur b'Hana'ah, e.g. Kodshim that left their Mechitzah (where they are permitted). [The Gemara] expounds in Chulin (68a) from "v'Vasar ba'Sadeh [Tereifah]" - once [meat] left its Mechitzah, it is forbidden.

Implied question: The simple meaning of the verse discusses Heter Hana'ah, like it is written "la'Kelev Tashlichun Oso"!

Answer: The Tana there holds that the Kal v'Chomer helps for this, that we learn from Kodshim, which the verse was also discussing;

And the Tana here holds that we learn from Tereifah, which is Mutar b'Hana'ah, like the simple meaning. He does not hold that there is a Kal v'Chomer.

Support: Likewise, the one who expounds Isur Hana'ah from the three times it is written "Lo Sevashel", he does not hold that there is a Kal v'Chomer.

Question: The one who expounds from [a Gezeirah Shavah from] Kodesh holds that there is a Kal v'Chomer. He should learn Isur Hana'ah from "b'Chol Kodesh ba'Esh Tisaref", like we learn [Isur Hana'ah of] Pasul Kodshim from it in Pesachim (24a)!

Answer #1: "Am Kadosh" and "Anshei Kodesh" pertains to the same matter (they discuss people), and they resemble each other (so we learn a Gezeirah Shavah between them. "B'Chol Kodesh" discusses Kodesh meat.)

Answer #2: We learn Chulin from Chulin, and we do not learn Chulin from Kodshim, like it says in Chulin (85a).

Assertion: The text does not say "and Chelev", for one cannot say that it does not need Hechsher;

If it is Chelev of a Neveilah, it does not have severe Tum'ah, for it says "Ye'aseh l'Chol Melachah." Why should it not need Hechsher?!

Suggestion: Perhaps it is of a Shechutah, and [it does not need Hechsher] because it already was Huchshar [through Shechitah].

Rejection: We learned in Chulin (128a) that R. Akiva retracted to teach like R. Yehudah, that Hechsher of Shechitah does not help for Chelev, for it is not yet a food, for in villages it is not eaten, until he intends [to eat] it! The text does not say in Taharos. Until here is from Rashi.

Remark: I wrote this because there are Perushim [versions of Perush Rashi] in which this was not written. Perhaps afterwards it was corrected.

Implied question: Rav Papa establishes there in Chulin (128a) an argument of Tana'im about Hechsher before intent!

Answer: Even so, it is reasonable that that Stam Mishnah of Maseches Taharos holds that he retracted.

Distinction: In the Seifa, the text properly says "Chelev in markets does not need intent or Hechsher", and it discusses Chelev of a Shechutah. Also Rashi explained so.

Explanation #1 (Rashi): [Villagers] are poor, and they do not regularly eat birds.

Explanation #2: It seems that in markets there are many eaters, and they buy everything. In villages there are few eaters, and they buy only good things.

Implied question: Why is there a difference between [Neveilah] of Tamei and Tahor [species]? Both of them are sold only to Nochrim, and they prefer pork!

Sources: It says in Chulin (17a, in Eretz Yisrael you will find) "u'Vatim Mele'im Kol Tuv" - sides of pork. And we say in Megilah (13a) "va'Yshaneha l'Tov" - [Esther was fed] sides of pork.

Answer: In any case, being Tahor makes it a food when it is slightly proper, since when it is not a Neveilah, it is a fully-fledged food for Yisrael.

Support #1: And for this reason Simanei Taharah help according to R. Shimon for a camel, hare and hyrax and pig, to make it a food, like it says below.

Support #2: Also Rashi explained here that Nivlas Behemah Temei'ah, wherever it is, Stam it is not destined to be eaten, for it is despised;

Also, it is rejected for two reasons. Firstly, it was not slaughtered. And also, it is Tamei.

Regarding Nivlas Behemah Tehorah, he explained that Stam, it is destined for Nochrim to eat it, for it is not despised. Also, regarding Yisrael it is rejected for only one reason. Therefore, it does not need intent.

Explanation (Rashi): [In the market, people] regularly eat birds and lard.

Inference: All lard is called Chelev. We do not discuss only Chelev that is forbidden, e.g. a membrane covering [the Kerev] that can be peeled off (Chulin 49b).

Explanation (Rashi): [If the blood] fell on [detached] vegetation, it was Machshir it, and all the more so if he did a proper Shechitah, the blood is Machshir even [the raven] itself, for its Shechitah is intent [to eat it];

If he killed it through Nechirah (tore the Simanim), R. Eliezer would not argue. Surely its blood is Machshir others, but not itself, for it itself does not receive Tum'ah without intent. Until here is from Rashi.

Objection: What he explained is astounding, that blood of Nechirah is Machshir others. Why is it Machshir, since it is not Dam Shechitah? "Dam Chalalim" does not apply to animals, only to people!

Observation: The same applies to all 24 [Tamei species of] birds, except for the Nesher (vulture or eagle), like is proven in Chulin (61b).

Explanation: And even if he did Nechirah (the blood should be Machshir), for also Lehis'asek (he was not engaged in Shechitah) is not Shechitah, and it is as if he did Nechirah to it.

Implied question: [If he was Mis'asek, the bird] would not be Huchzak through Dam Shechitah!

Answer: Even so he asks, since [the Beraisa] does not comes to teach that Dam Shechitah is Machshir, for we already know this, and it comes to teach only that intent is not required, since it has Simanei Taharah...

It could have taught this without [discussing] Shechitah!