1) RAV CHISDA'S OPINION WITH REGARD TO THE PROHIBITION OF "SHECHUTEI CHUTZ"
QUESTION: Rav Chisda rules that one is liable for slaughtering an animal outside of the Azarah ("Shechutei Chutz") when he slaughters an animal which, under any circumstances, is fit to be a valid Korban (as long as it is not "Mechusar Ma'aseh," lacking an essential requisite to be a Korban).
The Gemara challenges Rav Chisda's opinion from a different statement that he made. The Gemara in Pesachim (70b) teaches that a Korban Pesach slaughtered during the rest of the year she'Lo Lishmo (to be offered as a Korban Shelamim) is a valid Korban Shelamim. Rav Chisda states that one who slaughters a Korban Pesach during the rest of the year outside of the Azarah ("ba'Chutz") Lishmo (for the sake of a Korban Pesach) is not liable for "Shechutei Chutz." Since he slaughtered it Lishmo, it remains a Korban Pesach, which is not a valid Korban at any time of the year other than the fourteenth of Nisan. If he slaughtered it she'Lo Lishmo (to be offered as a Korban Shelamim) he is liable for Shechutei Chutz, because he slaughtered a valid Korban outside of the Azarah.
The Gemara infers from this statement that Rav Chisda maintains that one who slaughters a Korban Pesach outside of the Azarah with no explicit intention ("Stam") is also exempt, because it is not fit to be offered as a Korban Pesach on that day. This contradicts Rav Chisda's other statement that one transgresses the prohibition of Shechutei Chutz when he slaughters any animal which is fit to be offered as a Korban. A Korban Pesach slaughtered "Stam" could be offered as a Korban Shelamim if one has in mind during the Shechitah that it is l'Shem Shelamim, and thus he should be liable for slaughtering it ba'Chutz, even "Stam"! Why does Rav Chisda say that one is exempt for slaughtering it "Stam" outside of the Azarah?
The logic of the Gemara's question is difficult to understand. Rav Chisda says nothing about a Korban Pesach that one slaughters "Stam." From where does the Gemara infer that Rav Chisda maintains that one who slaughters a Korban Pesach "Stam" (during the rest of the year) outside of the Azarah is exempt? The Gemara cannot infer this from Rav Chisda's statement that one who slaughters the Korban Pesach she'Lo Lishmo is liable, which implies that one who slaughters it "Stam" is exempt, because the opposite inference can be made from the first part of his statement: Rav Chisda says that one who slaughters the animal Lishmo outside of the Azarah is exempt, which implies that one who slaughters it "Stam" is liable. What is the Gemara's question on Rav Chisda?
(a) TOSFOS (DH Ta'ama) suggests (and the RITVA explains at greater length) that according to Rashi, the Gemara assumes that Rav Chisda's intention was to discuss a case of "Stam," and not just the cases of Lishmo and she'Lo Lishmo. Since the Halachah is that all Korbanos that are slaughtered "Stam" are considered to have been slaughtered Lishmo, presumably when Rav Chisda discusses one who slaughters the Korban Pesach "Lishmo" he refers to one who slaughters it "Stam." Consequently, when Rav Chisda says that one who slaughters the animal "Stam" outside of the Azarah is exempt, he contradicts his other statement.
(b) Tosfos cites RABEINU TAM who answers that the Gemara's question is based on the beginning of Rav Chisda's statement. (Rabeinu Tam's text of the Gemara does not include the words that specify "Stam" as the contradictory case.) Rav Chisda says that one who slaughters a Korban Pesach Lishmo ba'Chutz is exempt, because a Korban Pesach slaughtered Lishmo in the Azarah after the fourteenth of Nisan is invalid. If, however, one slaughters it "Stam," it is fit to be offered as a Korban. The Gemara at this point understands that an "Akirah" is not necessary; the Korban automatically becomes a Shelamim when it is slaughtered "Stam," and the owner does not need to verbally declare it a Shelamim. There is no difference between a Korban Pesach slaughtered l'Shem Shelamim and one slaughtered "Stam." Accordingly, when one slaughters it Lishmo outside of the Azarah he should be liable for Shechutei Chutz, because the animal would have been fit to be offered as a Korban (Shelamim) had it been slaughtered "Stam" (and it is not Mechusar Ma'aseh).
Rashi's original text apparently conforms with Rabeinu Tam's Girsa, because Rashi emphasizes that the words "Ta'ama d'Lo Lishmo..." must be added to the text of the Gemara. Tosfos, on the other hand, says that there is no need to add any words. The TOSFOS YESHANIM comments that Rabeinu Tam's explanation is so straightforward that it is difficult to understand why Rashi changes the Girsa and gives a different explanation.
Perhaps Rashi and Rabeinu Tam are consistent with their respective opinions as expressed elsewhere. According to one opinion, an animal that was designated as a Korban Pesach does not require "Akirah" to become a valid Shelamim. Does this mean that the animal automatically becomes a Korban Shelamim when it is slaughtered after Pesach passes, regardless of the intent of the one who slaughters it, or does it mean that it becomes a Korban Shelamim only if the Shochet has nothing in mind (but not if the Shochet has in mind that it is a Korban Pesach)?
Rabeinu Tam in Pesachim (64a, cited by TOSFOS DH Ta'ama) says that according to the opinion that no "Akirah" is necessary, after the first day of Pesach passes an animal designated to be a Korban Pesach automatically becomes a Korban Shelamim since it can no longer be offered as a Korban Pesach. Even if one slaughters it Lishmo (with intent that it is a Korban Pesach) it remains a Shelamim. There is no such thing as a Korban Pesach after Pesach has passed, and thus the Korban remains a Shelamim. (In fact, it is not clear why, according to Tosfos, the Gemara here presumed that the Korban would be invalid when slaughtered in the Mikdash l'Shem Pesach, according to those who maintain that "Akirah" is not necessary. The Korban should remain a Shelamim that was slaughtered l'Shem Pesach, which is valid, as Tosfos writes here in Yoma! Apparently, the Gemara here assumes that all Shelamim slaughtered l'Shem Pesach are actually invalid, as the Gemara suggests earlier on 60b.)
Rashi, in contrast, maintains that even if a Korban Pesach does not need Akirah to become a valid Korban Shelamim, this does not mean that it becomes a valid Shelamim regardless of the intent with which it is slaughtered. If it is slaughtered l'Shem Pesach, the intent of the Shochet renders it a Korban Pesach she'Lo b'Zemano, which is an invalid Korban. (In a case in which the intent of the Shochet actively disqualifies the Korban, the logic of "Ho'il" does not apply to make one liable for slaughtering it outside of the Azarah. Therefore, the Gemara would not have asked that one should be liable for slaughtering the animal l'Shem Pesach outside of the Azarah (if "Akirah" is not necessary), unlike Rabeinu Tam suggests.) (The Ritva seems to understand Rashi as suggested above.)