Text: This is as is apparent from the Gemara in Yoma (12a).

Explanation: The words "they do not sell" is as if it says "they do not buy." Just as when the customer made a purchase from the butcher based on weight he can deduct the weight of the Matnos Kehunah from what he has to pay, as when he asked for a Litra of meat he had not intention to buy Matanos he would have to give to the Kohen, so too is the case in our Mishnah.

Explanation (cont.): If he left it by the seller it is as if he bought by weight, and he did not buy the Matanah of the Kohen. However, if he did not leave anything by the seller it is impossible to say he did not buy it, as he bought everything!

Implied Question: However, the Gemara's conclusion "that this is when the seller says he is not selling the Matanos" does not fit with what we have stated.

Explanation: It is also applicable to Matanos. The Gemara chose one of the two (when it stated Reishis ha'Gez).

Question: This is difficult. Since there is no difference between Chulin and Mukdashim (in all of the Mitzvos discussed in our Mesechta) aside from Gid ha'Nasheh and Oso v'Es Beno, they also could have said that this statement is never required in the Mishnah besides for the exception of Oso v'Es Beno!

Answer: Since it is a novel teaching regarding Gid ha'Nasheh that it is not required, as explained later in the Gemara when it says, "And don't we establish etc." it is better to exclude Gid ha'Nasheh that I would have thought needed to be said but truthfully it does not need to be said.

Explanation: When the Mishnah (89b) teaches that offspring of Kodshim is either holy in the womb or only when it comes out of its mother, it could have taught this without discussing Gid ha'Nasheh.

Explanation (cont.): However, once the Mishnayos had to state "regarding Chulin and Mukdashim" in most of the Mishnayos in our Mesechet, it also stated this regarding Gid ha'Nasheh where it did not need to be stated. Even so, we say that it must be referring to offspring of Kodshim, since we can explain that it is teaching us a somewhat novel lesson.

Opinion #1: Rashi explains that the reason is because the Torah would not say that you should send away the bird if it is forbidden to eat (and someone else may eat it).

Question #1: This is difficult, as the Gemara's terminology does not imply that this understanding is correct.

Question #2: Additionally, the Gemara concludes and establishes the case (regarding the killer bird) as where its ruling was not yet handed down. If so, it is not forbidden to eat and cannot cause one who does so to transgress!

Opinion #2: It seems that the Gemara is explaining the simple meaning of the Pasuk. The Pasuk implies that Shiluach ha'Ken only applies to something one can send away, not to a bird which a person is supposed to bring to the caretaker of Kodshim birds.

Explanation: Rashi explains that from "you should take for yourself" one cannot derive this, as one cannot transgress Meilah nor have benefit from Hekdesh eggs of turtledoves.

Explanation (cont.): Despite the fact that one could transgress Meilah if these eggs were regular Hekdesh items, everyone holds that our Mishnah is referring to Kodshei Mizbe'ach. The argument later is regarding regular Hekdesh. This is why we could not exclude Hekdesh from "take for yourself."

Implied Question: However, the terminology "to bring it to the caretaker" does not seem very accurate here, as a caretaker is only relative when discussing regular Hekdesh.