Numbers 18:7 WEB

⁵  You shall keep the charge of the sanctuary, and the charge of the altar; that there be wrath no more on the children of Israel.

⁶  I, behold, I have taken your brothers the Levites from among the children of Israel: to you they are a gift, given to Yahweh, to do the service of the tent of meeting.

⁷  You and your sons with you shall keep your priesthood for everything of the altar, and for that within the veil; and you shall serve: I give you the priesthood as a service of gift: and the stranger who comes near shall be put to death.

⁸  Yahweh spoke to Aaron, I, behold, I have given you the charge of my heave-offerings, even all the holy things of the children of Israel; to you have I given them by reason of the anointing, and to your sons, as a portion forever.

⁹  This shall be your of the most holy things, [reserved] from the fire: every offering of theirs, even every meal-offering of theirs, and every sin-offering of theirs, and every trespass-offering of theirs, which they shall render to me, shall be most holy for you and for your sons.