A father is commanded to redeem his wife’s first-born son (305:1-2,17,21-22) provided he is viable and was born through the birth canal (305:12,23-24). The redemption is done by personally giving money or movable property as a gift to a KOHEN (305:3-4,7-10,13,16); on the amount required see 305:1,5-6 and on cases of doubt see 305:14,25-31. The father first recites the blessings “…Who commanded us about redemption of the son” and “…Who kept us alive…” (305:10). The redemption should be done as soon as the son is 30 days old, but not on a Sabbath or holiday (305:11); it should be done even if the son died after reaching that age (305:12). If the father did not redeem the son he must redeem himself when he grows up; the court does not redeem him (305:10,15). This commandment does not apply if either the father or mother is a KOHEN or a Levite; see 305:18-19. It applies even if the son was conceived before the mother became Jewish (305:20).
We are commanded to sanctify the male first-born of a kosher BEHEMAH and to give it to a KOHEN (306:1). When the Temple existed it had to be offered as a sacrifice. It should be given to a KOHEN after it is 30 days old (50, for cattle) and must be cared for until then or until a KOHEN is available (306:2-3). The KOHEN must accept it (see 306:4) and may then sell or give it to anyone who needs it (see 306:6;307:3). It must be cared for until it acquires a permanent blemish (see 313:5) that would make it unfit for a sacrifice (306:5), after which it may be slaughtered and eaten by anyone (306:5) and no part of it need be given to a KOHEN (see 61:19-20); but if the slaughter was invalid it is forbidden to derive benefit from any part of it (307:2). The blemish must be conspicuous (see 309:2;315:5) and must be confirmed by three qualified, disinterested persons (309:2;310:3;312:1-2). If it was slaughtered before this was done it is forbidden to derive benefit from it (310:1-2). It is forbidden to kill it (309:1) or to make a blemish in it (even indirectly; 313:1) after it is born (313:7;319:1). If it was deliberately given a blemish it must not be slaughtered until it acquires another blemish (313:1-4,6). If it acquires a blemish during its first year it should be eaten by 30 days after the end of the year; if it acquires one after its first year it should be eaten within 30 days (306:7-12). After it is slaughtered it should not be skinned in one piece (307:1) and its meat should not be sold publicly (see 306:6). Before it is slaughtered it is forbidden to shear it or do work with it, and even after it dies or is slaughtered it is forbidden to derive benefit from anything taken from it while it is alive (308:1-3). On mixtures containing such things see (308:4-5).
A first-born must be born through the birth canal (315:2;319:3), must resemble its mother’s species (see 315:5-6), and must not have been preceded even by a non-viable birth (see 315:7). It is regarded as born when most of it has come out; see 319:1-4. On cases of doubt see 315:1-4;316:1-6; 317:1-3;318:1-5. A doubtful first-born need not be given to a KOHEN but must otherwise be treated as though it were a first-born (318:6). On trustworthiness about first-born see 311:1;314:1-11. If the owner of a first-born is a KOHEN he may keep it (320:1). If the first-born or its mother belongs in part to a non-Jew the laws of the first-born do not apply (320:3-7; see 320:2).
A first-born [male] donkey (see 321:23) must be redeemed (321:1,12); until this is done it is forbidden for anyone to derive benefit from any part of it alive or dead (321:8-9), but after it is done the donkey becomes permissible (321:1,6). The person who redeems it first recites the blessing “…Who commanded us about redemption of a donkey’s first-born” (321:6). It is redeemed by giving its value (but not less than a certain amount; see 321:5) to a KOHEN or by giving a live sheep or goat to a KOHEN (see 321:1-4); this gift has no sanctity and may be used in any way by the KOHEN (321:1). If the donkey’s owner does not want to redeem it he may kill it (see 321:8,10); this should be done by stabbing it in the back of the neck (321:11-12). The donkey itself should not be given to a KOHEN; if it was he must redeem it or kill it (321:8). If someone redeems another person’s donkey it still belongs to its owner (321:7). On cases of doubt see 321: 13-16,18; a doubtful first-born must also be redeemed but the redemption need not be given to a KOHEN (321:10). This commandment does not apply to a donkey that is partly owned by a male or female KOHEN or Levite (321:17,19,21) or by a non-Jew (321:20,22).
Shulchan Aruch, Copyright (c) 2000 ProjectGenesis, Inc.