Leviticus 7:34-36

34for the breast of the wave offering and the thigh of the contribution offering I have taken from the Israelites out of their peace offering sacrifices and have given them to Aaron the priest and to his sons from the people of Israel as a perpetual allotted portion.’”

35This is the allotment of Aaron and the allotment of his sons from the Lord’s gifts on the day Moses presented them to serve as priests to the Lord.

36This is what the Lord commanded to give to them from the Israelites on the day Moses anointed them – a perpetual allotted portion throughout their generations.