Exodus 29:26-28

29:26 You are to take the breast of the ram of Aaron’s consecration; you are to wave it as a wave offering before the Lord, and it is to be your share. 29:27 You are to sanctify the breast of the wave offering and the thigh of the contribution, which were waved and lifted up as a contribution from the ram of consecration, from what belongs to Aaron and to his sons. 29:28 It is to belong to Aaron and to his sons from the Israelites, by a perpetual ordinance, for it is a contribution. It is to be a contribution from the Israelites from their peace offerings, their contribution to the Lord.

Leviticus 7:31-34

7:31 and the priest must offer the fat up in smoke on the altar, but the breast will belong to Aaron and his sons. 7:32 The right thigh you must give as a contribution offering to the priest from your peace offering sacrifices. 7:33 The one from Aaron’s sons who presents the blood of the peace offering and fat will have the right thigh as his share, 7:34 for 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.’”