Chapter 164 – Redemption of the Firstborn
164.1) Every Jew has a duty to redeem the firstborn son.
164.2) You should not retract the redemption of a son from a kohen (priest) you have made a promise to.
164.3) Do not redeem the firstborn until he is fully thirty days old.
164.4) The father brings his firstborn before the Kohen, gives him something worth five selaim, places him before the Kohen, and says the appropriate benediction. See the source for details.
164.5) If the father is not at home, he may redeem his son wherever he is.
164.6) The kohen traditionally returns half the money to the father.
164.7) A mother is not bound to redeem her son if the father has died. The Beth Din redeems him.
164.8) If a son is not redeemed, he is obligated to redeem himself when he is grown.
164.9) Priest and Levites are exempt from redeeming their firstborn sons.
164.10) Redemption of an infant after the mother has had an abortion previously should be presented to a rabbi for instructions.