Numbers 18:12-15

12“I also give you the harvest gifts brought by the people as offerings to the Lord—the best of the olive oil, new wine, and grain.

13All the first crops of their land that the people present to the Lord belong to you. Any member of your family who is ceremonially clean may eat this food.

14“Everything in Israel that is specially set apart for the Lord also belongs to you.

15“The firstborn of every mother, whether human or animal, that is offered to the Lord will be yours. But you must always redeem your firstborn sons and the firstborn of ceremonially unclean animals.