Leviticus 7:34-36

34I have taken from the Israelites the breast of the presentation offering and the thigh of the contribution from their fellowship sacrifices, and have assigned them to the priest Aaron and to his sons as a permanent portion from the Israelites.”

35This is the portion from the food offerings to the Lord for Aaron and his sons since the day they were presented to serve the Lord as priests.

36The Lord commanded this to be given to them by the Israelites on the day he anointed them. It is a permanent portion throughout their generations.