Numbers 18:15-17

Modern English Version

¹⁵ Everything that opens the womb of all flesh, which they bring to the Lord, whether it is of men or animals, will be yours. However, you will surely redeem the firstborn of man, and the firstborn of unclean beasts you will redeem. ¹⁶ Their redemption price, reckoned from one month of age, is five shekels,^[a] after the shekel of the sanctuary, which is twenty gerahs.

¹⁷ But the firstborn of a herd animal, or the firstborn of a sheep, or the firstborn of a goat, you will not redeem. They are holy. You will splash their blood on the altar and will burn their fat as a fire offering, as a pleasing aroma to the Lord.