6I myself have chosen the descendants of Levi from the other Israelis in order that they may be your special helpers. They are like a gift that I have given you to work at the Sacred Tent.
7But it is you and your sons, who are the priests, who must perform all the rituals concerning the altar and with what happens inside the Very Holy Place. I am giving to you this work of serving as priests. So anyone else who tries to do that work must be executed.”
8Yahweh also said to Aaron, “I myself have appointed you to take care of all the sacred offerings that the Israeli people bring to me. I have given all these sacred offerings to you and to your sons. You and your descendants will get a share of these offerings permanently.
9The parts of the offerings that are not completely burned on the altar belong to you. Those parts of the sacred offerings, including the offerings of grain, the offerings for sins and for the people to be forgiven for not giving me what they are required to give, are set apart, and are to be given to you and your sons.
Numbers 18
Numbers 18:6-9