Numbers 18:15-20

1512Every firstborn of the womb of all flesh, whether human or animal, which they offer to the Lord, shall be yours; however you must redeem the human firstborn, and the firstborn of unclean animals you shall redeem. 16As to 3their redemption price, from a month old you shall redeem them, by your assessment, five 4shekels in silver by the 5shekel of the sanctuary, which is twenty gerahs. 17But 6the firstborn of an ox, the firstborn of a sheep, or the firstborn of a goat, you shall not redeem; they are holy. 7You shall sprinkle their blood on the altar and offer up their fat in smoke as an offering by fire, for a soothing aroma to the Lord. 18However, their 8meat shall be yours; it shall be yours like the 9breast of a wave offering and like the right thigh. 1910All the offerings of the holy gifts, which the sons of Israel offer to the Lord, I have given to you and your sons and your daughters with you, as a permanent allotment. It is 11a permanent covenant of salt before the Lord to you and your 12descendants with you.” 20Then the Lord said to Aaron, “13You shall have no inheritance in their land nor own any portion among them; 14I am your portion and your inheritance among the sons of Israel.