Redeeming the Firstborn Donkey With a Living Lamb

"And every firstling of a donkey" (Exodus 13:13): and not the firstling of a camel, nor the firstling of a horse. From here they said: a female donkey that had not previously given birth and bore something resembling a camel or a horse, and likewise a female camel that had not previously given birth and bore something resembling a camel or a donkey, is exempt from the law of the firstborn, as it says "firstling of a donkey, firstling of a donkey" twice, [teaching] that the one giving birth and the one born must both be a donkey. Rabbi Meir says: it states, "But the firstling of an ox" (Numbers 18:17) as a general rule. The firstling of an ox is one born an ox; the firstling of a sheep is one born a sheep; the firstling of a goat is one born a goat. One might think this applies even if it bears only some of the signs resembling its mother; therefore Scripture says "but [only]." "You shall redeem": immediately; "you shall redeem" with anything of value. Rabbi Yose son of Rabbi Yehudah says: not less than the weight [of a fixed amount]. "With a lamb": I might hear this to mean a living lamb or a slaughtered lamb. You reason: "lamb" is stated here and "lamb" is stated elsewhere; just as the "lamb" stated elsewhere is a living lamb and not a slaughtered one, so the "lamb" stated here is a living lamb and not a slaughtered one. "With a lamb": and not with a slaughtered one, nor with a torn one, nor with a crossbred animal, nor with a koy [an animal of doubtful species]. One might think that if he redeemed it while still in its mother's womb it is redeemed; therefore Scripture says, "And if you do not redeem it, then you shall break its neck" (Exodus 13:13). That which is subject to having its neck broken is subject to redemption; that which is not subject to having its neck broken is not subject to redemption. One might think that if he redeemed it after death it is redeemed; therefore Scripture says, "And if you do not redeem it, then you shall break its neck": that which is subject to redemption is subject to having its neck broken, and that which is not subject to redemption is not subject to having its neck broken. "You shall break its neck": "breaking the neck" is stated here and "breaking the neck" is stated elsewhere (Deuteronomy 21:4); just as the "breaking the neck" stated elsewhere is done with a cleaver from behind, and it is buried, and benefit from it is forbidden, so the "breaking the neck" stated here is done with a cleaver from behind, and it is buried, and benefit from it is forbidden. "And every firstborn of man among your sons you shall redeem": why do I need this, when it already says, "And every firstborn of my sons I redeem" (Exodus 13:15)? He is to redeem himself and to redeem his son; he takes precedence. "My sons I redeem," even after death.