Numbers 18:14-16

Amplified Bible

¹⁴ Every devoted thing in Israel [everything that has been promised to the Lord with an oath] shall be yours. ¹⁵ Every firstborn of the womb of all flesh, whether it is man or animal, which they bring to the Lord, shall be yours; nevertheless, the firstborn of man you shall most certainly redeem, and the firstborn of unclean animals you shall redeem. ¹⁶ And their redemption price, from a month old you shall redeem, according to your ^[a]valuation, for the [fixed] price of five shekels in silver, in accordance with the shekel of the sanctuary, which is twenty gerahs.