Halakhah zu Schemot 13:13

The commandment of the redemption of a [first-born] donkey: To redeem the male offspring of a donkey that was born first, as it is stated (Exodus 13:13), "And the first-born of a donkey, you shall redeem with a sheep." And its content is that the Israelite takes one sheep and gives it to the priest as redemption for the first-born donkey, which is to God, for the reason that we wrote above. And He, blessed be He, gave it to the priest. And hence the Israelite redeems it from him, since God, may He be blessed, wanted that there should be a redemption for it with a sheep. And if he does not have a sheep, he redeems it with the money [value] of a sheep. And since the money of sheep is not the same [in all cases], the Rabbis, may their memory be blessed, said (Bekhorot 11a), "A good eye (a generous price) is a sela, a bad eye (a miserly price) is half a sela, an intermediate [one] is three zuz." And the time of the redemption is until thirty days. And the sheep is non-sanctified in the hand of the priest and the donkey is [likewise] in the hand of the Israelite.

The commandment of beheading a [first-born] donkey: To behead a [first-born] donkey, if he does not want to redeem it, as it is stated (Exodus 13:13), "and if he does not redeem it, he shall behead it." Its content is that he kills the offspring of the donkey if he does not want to redeem it. And God decreed that he should not benefit from it, since he did not redeem it. And [this is such] that even the carcass is forbidden for him to benefit from.

Our Rabbis also taught us that in our time, we do the redemption of the first-born in an order like this: They bring a cup of wine and a myrtle branch to the home of the father of the son or to [some] other place, and the priest to whom the father chooses to give the redemption of his son blesses first over the wine and over the myrtle and then recites this blessing - "Blessed are You, our Lord, King of the Universe, Who sanctified the fetus in his mother's innards, and at forty days individuated his limbs into two hundred and forty-eight limbs, and then breathed in the spirit of life, as it is written (Genesis 2:7), 'and He breathed in his nostrils ...'; He clothed him with skin and flesh, and covered him with bones and ligaments, as it is written (Job 10:11), 'He clothed me with flesh and skin and covered me with bones and ligaments.' He appointed food and drink for him, honey and milk to bring him joy, and appointed two ministering angels to guard him in his mother's womb, as it is written (Job 10:12), 'with life and kindness, etc.'" His mother says, "This is my firstborn son, with which God opened the doors of my belly." His father says, "This is my first-born and I am warned about redeeming him, as it is stated (Exodus 13:13), 'and all the first-born of man, your sons shall you redeem.' May it be the will in front of You, Lord, my God, that as You have allowed his father to merit to redeem him, so too should you allow him to merit Torah, marriage and good deeds. Blessed are You, Lord, who sanctified the first born of Israel to be redeemed." The father of the son then recites two blessings: 'on the redemption of the first born'; and 'Who has allowed us to live.' He gives the well-known redemption to the priest, which is five sela, as specified in the Torah. This is equal to sixty argents of refined silver in our land. And after the redemption, the priest recites these three blessings that we wrote.