He had the opportunity...
Here we’ll talk about the situation of a lamb that was redeemed but died while it was still in the owner’s hands. We’ll have a machloket (dispute) about this. The Mishnah says: If somebody designated a lamb as the redemption for the Peter Chamor (firstborn donkey), but the lamb died before it was given to the Kohen (priest), the owner is responsible for the lamb and has to give a replacement to the Kohen. In a similar case, if a father had the five sela’im (sela coins) for the redemption of a firstborn, and they were lost before he gave them to a Kohen, the father would be responsible until the Kohen receives the money. Likewise, over here, the owner of the Peter Chamor would be responsible for the lamb until the Kohen receives it.
We learn this from a pasuk (verse). It says, talking about the mitzvah (commandment) of Peter Chamor. Then it says, “The firstborns of your sons you should redeem.” So we see a connection between the Peter Chamor and the redemption of a regular human. But we’ll have a machloket here. The Hachamim (Sages) say the owner is not responsible for the lamb, just as the owner would not have to replace the redemption money of Ma’aser Sheni if it was lost before it was brought to Yerushalayim. Ma’aser Sheni basically takes effect right away, as soon as the owner transfers the holiness onto the money, and it remains valid no matter what happens to the money afterward. So if the money was lost afterward, that’s not the responsibility of the owner. There’s innate Kedushah; there’s innate holiness on those Ma’aser Sheni coins. So likewise, we’d say over here that once the Peter Chamor is redeemed, as soon as the owner declares that the lamb is a redemption for the chamor (donkey), that redemption happens, and the owner would not be responsible anymore.
A quick note, of course: Ma’aser Sheni is the fruits that a person has to bring into Yerushalayim and eat there, but he doesn’t want to have the burden of carrying them there, so he transfers the holiness onto coins. He has to increase the amount; he has to add Chomesh (a fifth), and he would bring those coins to Yerushalayim and spend them on food there. So that’s a machloket, really, as it compares this to Pidyon HaBen (redemption of a regular human), where the owner would be responsible until it reaches the hands of the Kohen, while Hachamim say it’s comparable to Ma’aser Sheni, where once the money has been turned into Ma’aser Sheni funds, what happens to it afterward is not the responsibility of the owner.
Now we’ll have support for that position of the Hachamim. He’id Rabbi Yehoshua and Rabbi Tzadok—these two rabbis testified—that, in the case of Pidyon Peter Chamor shemet, a firstborn redemption lamb for the donkey that died before the owner gave it to the Kohen, the Kohen is not entitled to anything else afterward. That fits with the position of the Hachamim: the owner is not responsible for the dead lamb, since the Peter Chamor was already redeemed. And the lamb’s body, its carcass, would belong to the Kohen, since at that point in time, the lamb became his property right when the owner declared the redemption.
Now we’ll talk about where the donkey died, not the lamb, before the lamb was handed over to the Kohen. Met Peter Chamor—if the Peter Chamor died after the redemption lamb was designated but before it was given to the Kohen—Rabbi Eliezer says, yikaver u'mutar behana’ato shel taleh: the Peter Chamor is to be buried, and the owner is permitted to benefit from the lamb. You’re not allowed to benefit whatsoever from the Peter Chamor. So, according to Rabbi Eliezer, the Peter Chamor is not redeemed until the owner gives the lamb to the Kohen. The donkey died before that handover, so no one may benefit whatsoever from its carcass. It has to be buried, and no one is allowed to benefit from it.
And this is the inverse. If the redemption ever happened, then the lamb is the property of the owner. Therefore, as long as the lamb wasn’t handed over to the Kohen, there’s no redemption whatsoever, and the dead donkey doesn’t have to be redeemed whatsoever, so the lamb stays with the owner. The donkey does not need to be buried in their opinion. It was redeemed. The moment the redemption lamb was designated, even before it was given to the Kohen, the redemption happened. For that reason as well, the lamb has to be given to the Kohen, since it was redeemed and belongs to the Kohen, even though nothing was handed over yet. It has to be handed over, and we disregard what happens with the donkey. The fact that the donkey died, that was already a redeemed donkey. And now the lamb that was used for the redemption has to be given over to the Kohen.