Numbers 18:12-15

12All the best of the oil and all the best of the wine and of the grain, the firstfruits of what they give to the Lord, I give to you.

13The first ripe fruits of all that is in their land, which they bring to the Lord, shall be yours. Everyone who is clean in your house may eat it.

14Every devoted thing in Israel shall be yours.

15Everything that opens the womb of all flesh, whether man or beast, which they offer to the Lord, shall be yours. Nevertheless, the firstborn of man you shall redeem, and the firstborn of unclean animals you shall redeem.