Numbers 18:3-8

18:3 They must be responsible to care for you and to care for the entire tabernacle. However, they must not come near the furnishings of the sanctuary and the altar, or both they and you will die. 18:4 They must join with you, and they will be responsible for the care of the tent of meeting, for all the service of the tent, but no unauthorized person may approach you. 18:5 You will be responsible for the care of the sanctuary and the care of the altar, so that there will be no more wrath on the Israelites. 18:6 I myself have chosen your brothers the Levites from among the Israelites. They are given to you as a gift from the Lord, to perform the duties of the tent of meeting. 18:7 But you and your sons with you are responsible for your priestly duties, for everything at the altar and within the curtain. And you must serve. I give you the priesthood as a gift for service; but the unauthorized person who approaches must be put to death.”

The Portion of the Priests

18:8 The Lord spoke to Aaron, “See, I have given you the responsibility for my raised offerings; I have given all the holy things of the Israelites to you as your priestly portion and to your sons as a perpetual ordinance.