Leviticus 7:33-38

33 When any of Aaron's sons offer the blood and fat of the fellowship offering, the right thigh will belong to him as his share.
34 From the fellowship offerings of the Israelites, I have taken the breast that was presented [to me] and the thigh from the contribution offering. I have given them to the priest Aaron and his sons. This is a permanent law for generations to come.
35 "This is the share for Aaron and his sons from the sacrifices by fire made to the LORD. It was given to them on the day Moses ordained them to serve the LORD as priests.
36 The LORD commanded the Israelites to give it to them on the day he anointed them. This is a permanent law for generations to come."
37 These are the instructions for the burnt offering, the grain offering, the offering for sin, the guilt offering, the ordination offering, and the fellowship offering.
38 On Mount Sinai the LORD gave Moses commands about these offerings at the same time that he commanded the Israelites to bring their offerings to him in the Sinai Desert.