Exodus 29:26-28

26You 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.

27You 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.

28It 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.