Chullin, Chapter 2, Mishnah 10. Throughout this chapter the Mishnah has been mapping out what makes a shechitah succeed and what ruins it, and now it turns to what the slaughterer has in mind and says out loud. Picture a man who takes a plain, unconsecrated animal, slaughters it somewhere outside the Beit Hamikdash, and announces as he cuts that this shechitah is being performed in the name of an offering. What is the halachah?
The Background: Shechitat Chutz
Min haTorah, a korban may not be slaughtered anywhere except within the Beit Hamikdash. Whoever does so incurs karet, and the meat of that animal is forbidden to eat.
Our Mishnah, however, is dealing with something quite different. The animal before us is chullin, ordinary and unconsecrated, never designated as an offering at all. The only thing that happened is that the slaughterer announced that his shechitah was being done in the name of one korban or another. He never declared this animal itself to be holy. Since no consecration ever took place, min haTorah the meat is fit and he may eat it. What the Mishnah comes to clarify is whether Chachamim nonetheless placed a prohibition on it, and about that there is a machloket.
The First List: Korbanot That Can Be Brought Voluntarily
The Mishnah presents five cases. "HaShochet leshem olah," one who slaughters while declaring that this shechitah is that of an olah; "leshem zevachim," which here means shelamim; then "leshem asham talui," an asham talui; next "leshem pesach," the korban Pesach; and last "leshem todah," a todah. Concerning all five, "shechitatan pesulah," the shechitah is invalid. Keep the decisive detail in view: the animal is chullin, and the slaughtering happens away from the Beit Hamikdash.
An olah and shelamim both belong to the class of offerings that any person may bring whenever he chooses, with nothing obligating him. That is exactly what troubled Chachamim: if a man announces that he is slaughtering as an olah or as shelamim, those standing by are likely to assume that he had just now made this animal holy.
An asham talui comes from a person who is unsure whether he committed an aveirah, one that carries karet when done knowingly and calls for a chatat when done unwittingly. Picture two lumps of fat lying in front of him: one is chelev, forbidden min haTorah, and the other is ordinary shuman. He eats one of them, either knowingly or under the impression that both were permitted. Because he cannot establish which lump he ate, he brings an asham talui. Were it clear that the chelev was what he swallowed, a knowing act would leave him liable to karet and an unwitting act would obligate him in a chatat. As matters stand, the uncertainty itself, whatever his state of mind was, generates an obligation of asham talui.
The korban Pesach has only one day on which it is offered, Erev Pesach, yet an animal may be set aside for it at any point in the year and kept until the festival arrives. Should the owner slaughter it before that day, its avodah is conducted by the halachot that govern shelamim.
In every one of these five cases Chachamim declared the shechitah invalid miderabbanan, and the animal may not be eaten. Their fear ran as follows: bystanders would take for granted that the man had sanctified this animal moments before the cut, and then, watching the meat being consumed, they would walk away convinced that an offering slaughtered away from the Beit Hamikdash is permitted as food. To prevent such an error from ever taking hold, Chachamim invalidated the shechitah.
Rabbi Shimon Disagrees
"Rabbi Shimon machshir." Rabbi Shimon holds that the shechitah is valid. In his view there is no such concern that onlookers will reach that conclusion, and at bottom the man never consecrated anything and never made the animal holy at all.
Two Men Holding One Knife
"Shenayim ochazin besakin veshochtin": two men take hold of a single knife and cut together. One of them slaughters "leshem echad mikol eilu," intending one of the offerings enumerated a moment ago, while his partner slaughters "leshem davar kasher," with a wholly permissible intention. The ruling is nevertheless "shechitatan pesulah." The identical worry of Chachamim is present here: those watching may still walk away convinced that an offering slaughtered away from the Beit Hamikdash is permitted as food.
The common thread in everything listed so far is that these korbanot are offered voluntarily. An olah and shelamim may be brought by anyone who wishes to bring them, even someone under no obligation whatsoever. So when the slaughterer voices such an intention, it is entirely plausible to a bystander that he consecrated the animal on the spot, and Chachamim therefore decreed that the meat may not be eaten.
The Second List: Korbanot That Cannot Be Brought Voluntarily
"HaShochet leshem chatat," one who slaughters a chullin animal beyond the walls of the Beit Hamikdash while declaring this shechitah to be that of a chatat; "leshem asham vadai," an asham of certainty; "leshem bechor," a firstborn animal; "leshem ma'aser," ma'aser behemah; "leshem temurah," a substituted animal. In all of these, "shechitatan kesherah," the shechitah holds and the animal may be eaten.
Let us state the reasoning first and then walk through the individual cases. Not one of these offerings can be brought at a person's own initiative. Consequently no one suspects that this animal had received kedushah prior to the cut, and there is nothing here to prohibit, since everyone watching understands that the animal never became holy at all.
Chatat. A chatat is brought by someone who transgressed an aveirah that would have carried karet had it been done deliberately, and who in fact did it by mistake.
Asham vadai. There are five particular sins that obligate a person in a definite asham. The chatat and this asham are both compulsory offerings; a person cannot volunteer them, they come only in the wake of specific aveirot. And when someone sins, word gets around. He says vidui, he confesses aloud, he wants to experience the busha, the sense of shame, and that is the channel through which his kapparah reaches him. If no confession was ever made and his neighbors never heard that he did any such thing, they know full well that no offering of this kind is incumbent upon him. So when they see him slaughtering and hear him name a chatat, they grasp immediately that no animal here was ever set aside as one, for had the sin occurred they would have heard of it. An asham vadai works precisely the same way. Hence the shechitah is kesherah: it is plain to everyone that these animals never carried kedushah.
Bechor. When a person's cattle, goats or sheep give birth for the first time, the newborn becomes holy on its own the very instant it enters the world. Its owner hands it over to the kohen, and the kohen brings it as an offering.
Ma'aser. Each year the owner of cattle, sheep and goats gathers the young animals born that season and releases them from the pen one by one. Every tenth animal to come out is marked with red dye as ma'aser. In due course it is brought upon the mizbeach, and its meat is consumed by the owner along with those he invites to join him.
Kedushah of this kind attaches to an animal only through the circumstances just described, never by a spoken declaration. So if a man takes an animal and announces that his shechitah is that of a bechor or of ma'aser, no observer will entertain the notion that he had sanctified it as such, for the plain reason that nobody is able to. A bechor's holiness begins at birth, and ma'aser's begins when the animal emerges tenth from the pen. Beyond that, his neighbors would have been aware had he owned a bechor or a ma'aser animal that he was obligated to bring.
Temurah. Temurah is when a person owns a korban and attempts to substitute another animal in its place. He may not do this, and the substitute animal, the temurah, itself takes on a certain sanctity. When a person is holding a korban, that fact becomes known to those around him. If no one knows of any korban in his possession, he will not be suspected of having designated a substitute for it.
In each of these instances, then, the shechitah stands and the meat is permitted. Because none of these offerings can be brought at will, nobody will suspect that this animal received kedushah before the knife was drawn, and Chachamim found no cause to prohibit its meat.
The Klal
"Zeh haklal" - here is the governing principle. "Kol davar shenidar venidav, hashochet lishmo, asur": whenever a man slaughters a chullin animal away from the Beit Hamikdash and names an offering that can come as a neder or a nedavah, that is, one a person may bring of his own accord, the meat is prohibited. "Veshe'eino nidar venidav, hashochet lishmo, kasher": if the offering he named is one that cannot arrive by neder or nedavah, one that nobody can volunteer, the meat is fit to eat.