With good fortune we open a new tractate - Maseches Temurah, chapter one, mishnah one. As noted in the introduction, the entire tractate revolves around a single verse that appears in Parashas Bechukosai.
The foundational verse (Vayikra 27:10):
"Lo yachalifenu velo yamir oso" - one may not exchange or substitute a korban.
"Tov b'ra o ra b'tov" - whether he brings an unblemished, superior animal in place of an inferior, blemished one, or the reverse: an inferior, blemished animal in place of a consecrated, unblemished one.
"V'im hamer yamir behemah bivhemah" - when a person does in fact attempt to substitute one animal for another.
"V'hayah hu u'temuraso yihyeh kodesh" - both of them are holy. The substitution does not succeed in removing the sanctity from the first animal, but it does succeed in extending that sanctity to the second one as well.
"Hakol memirin, echad anashim v'echad nashim":
Having presented the prohibition, the Mishnah now establishes that any person has the power to create a temurah, male or female alike, and there is no reason to distinguish between them. This emphasis is needed because the language of the verse itself is written in the masculine: "lo yachalifenu velo yamir", and seemingly the Torah should have added "tachalifenu v'tamir" for women. Rather, the extra letter vav in the phrase "v'im hamer yamir" comes to include women together with men, with no difference between them.
What the word "hakol" adds:
Beyond men and women, this word comes to include the heir. The basic and central halachah in our sugya is that only the owner of the animal has the power to create a temurah; if someone who is not the owner attempts to do so, nothing takes effect at all. The novelty of "hakol" is that when the original owner - the father - passes away and bequeaths the consecrated animal to his son, the son is able to make a temurah even though he is not the original owner. This law too is derived from the verse: the seemingly redundant doubling in "hamer yamir" comes to teach that the heir is included as well.
"Lo she'adam rashai lehamir":
The Mishnah warns against confusing "able" with "permitted". It does not mean that a person is allowed to create a temurah - he is absolutely forbidden to do so. Its intent is that if he transgressed and made a substitution, meaning that he brought a chullin animal to serve as a substitute for a consecrated animal - "mumar" - that chullin animal becomes a temurah and is itself sanctified. Nevertheless, one who does this faces the consequences of his actions: "v'sofeg es ha'arba'im".
"Sofeg es ha'arba'im":
The plain meaning of the phrase is that he receives forty, and the intent is lashes, which in practice are forty less one - thirty nine lashes, since we do not administer a full forty lest the one being lashed die. Everywhere in Shas the expression "sofeg es ha'arba'im" simply means that he receives lashes. Obviously all the usual requirements for lashes must be met here, including two witnesses and prior warning; the point is that this person is liable to lashes.
The question of "a prohibition that involves no action":
The accepted principle is that a prohibition that involves no action - a violation committed through words alone rather than through an actual deed - does not carry lashes. Yet the act of temurah is performed entirely through speech: a person says "this one in place of that one" or "this is an exchange for that one." Why, then, are lashes given here?
The Bartenura follows the Rambam and establishes that this is indeed the rule, but there are three exceptions that do carry lashes even though they are performed with the mouth alone:
One who swears falsely.
Temurah - the case in our Mishnah.
One who curses his fellow using the name of Hashem.
It is interesting that the Bartenura chose this approach, since the Gemara offers a different distinction: in temurah something changes in the physical world, or at the very least a halachic change takes place. Before the substitution the animal was chullin, and afterward it became consecrated. This is not the case with one who swears falsely or curses his fellow, where nothing at all happened, not even a halachic change down here. Apparently, though, the Rambam, and the Bartenura following him, does not hold that a halachic change constitutes an action.
"HaKohanim memirin es shelahen v'Yisrael memirin es shelahen":
Since a person can effect temurah only with an animal he owns, it is understandable that a kohen who consecrated an offering of his own, and likewise a Yisrael who consecrated one of his own, can perform temurah with it. But "ein haKohanim memirin lo b'chatas v'lo b'asham v'lo b'vechor" - a kohen cannot effect temurah with a chatas or an asham that were given to him, nor with a bechor. These are two separate matters.
With the chatas and the asham, the case is that of a Yisrael who is not a kohen and who transgressed - for example, he desecrated Shabbos unintentionally - and must bring a chatas. He consecrates the animal, goes up to the Beis HaMikdash, and asks the kohen: "I desecrated Shabbos and I must bring an offering; this is my chatas, please perform it for me." The kohen performs the service, and afterward the kohanim receive the meat of the chatas to eat. Since the kohen has a share in it, one might have thought that he would be considered enough of an owner to effect temurah. But the answer is no: as long as the animal is alive, before it is slaughtered and offered, it belongs to the original owner, the Yisrael, and not to the kohen; and since the kohen has no share in it, he cannot effect temurah with it. This ruling is not much of a novelty, but the law of the bechor is far more surprising.
With the bechor, the case is a Yisrael who has a cow, a goat, or a ewe that became pregnant, and their first offspring is a male, a firstborn of the womb. The halachah is that this animal is given to a kohen and he becomes its owner, and if it has a permanent blemish the kohen may even eat it immediately, and it need not be offered at all. Seemingly he is its complete owner, and nevertheless the Mishnah rules that the kohen cannot effect temurah with a bechor that was given to him, and this is puzzling.
This very difficulty is raised in the Mishnah itself: "Amar Rabbi Yochanan ben Nuri" - why can the kohen not effect temurah with a bechor, when it is his? Rabbi Akiva answers with a comparison: just as the chatas and the asham are gifts to the kohen and the kohen is not their original owner, and therefore he cannot effect temurah with them, so too the bechor is a gift to the kohen, and he cannot effect temurah with it.
To this Rabbi Yochanan ben Nuri responds: "Mah li eino meimer b'chatas uv'asham she'ein zocheh bahen b'chayeihen, tomar b'vechor shezocheh bo b'chayav" - what do a chatas and an asham have to do with this? There, as long as the animal is alive it does not belong to the kohen at all. But the bechor belongs to the kohen entirely, and he may eat it immediately if it is blemished; and if someone stole it, the thief must pay the kohen. The animal is certainly his, and the cases are not comparable at all.
Rabbi Akiva said to him: the basis of the law is not logic but a derivation from the verse. Regarding temurah it says "v'hayah hu us'muraso yihyeh kodesh", and from here we compare the original offering to its substitute: where does its sanctity take effect? In the owner's house alone, for only the original owner is the one who consecrates the animal to begin with, and a person cannot consecrate something that is not his. When a person consecrates his chatas, his asham, or his bechor, it is done while the animal is still in the possession of the original owner, and not in the possession of the kohen who will receive it afterward. From here: the temurah as well takes effect only in the owner's house, meaning that only the original owner has the power to effect temurah.
It is worth understanding this point regarding the bechor: the original owner, whose cow, goat, or ewe gave birth to a firstborn, is indeed obligated to give it to a kohen, but he has a certain right in it - the right to choose which kohen will receive it. If one kohen comes and says, "I heard that a bechor was born to you last night, give it to me," the owner may reply, "A bechor was indeed born to me, but I am not giving it to you; I am giving it to my cousin who is a kohen." It emerges that the original owner has enough rights to be considered the owner of the animal, and therefore he is the one who can effect temurah with it, and not the kohen. This is the basis of Rabbi Akiva's position, derived from the verse, and this is also the halachah in practice.
To summarize: We can now clearly understand the novelty conveyed by the word "Hakol" - "All" - at the opening of the Mishnah. Since only the original owner can effect a temurah, and an heir is not the original owner, the Mishnah teaches us that the halachah here follows the rule found throughout the entire Torah - that heirs step into the shoes of the one who bequeathed to them and are treated as though they were he. Therefore an heir can effect a temurah even though he is not the original owner, whereas a kohen who receives a firstborn animal cannot; only the original owner himself can effect a temurah, and not the kohen.