Numbers 18:14-16

New Revised Standard Version, Anglicised Catholic Edition

¹⁴ Every devoted thing in Israel shall be yours. ¹⁵ The first issue of the womb of all creatures, human and animal, which is offered to the Lord, shall be yours; but the firstborn of human beings you shall redeem, and the firstborn of unclean animals you shall redeem. ¹⁶ Their redemption price, reckoned from one month of age, you shall fix at five shekels of silver, according to the shekel of the sanctuary (that is, twenty gerahs).