Numbers 18:5-7

Amplified Bible, Classic Edition

⁵ And you shall attend to the duties of the sanctuary and attend to the altar [of burnt offering and the altar of incense], that there be no wrath any more upon the Israelites [as in the incident of Korah, Dathan, and Abiram].^(A)

⁶ And I, behold, I have taken your brethren the Levites from among the Israelites; to you they are a gift, given to the Lord, to do the [menial] service of the Tent of Meeting.

⁷ Therefore you and your sons with you shall attend to your priesthood for everything of the altar [of burnt offering and the altar of incense] and [of the Holy of Holies] within the veil, and you shall serve. I give you your priesthood as a service of gift. And the stranger [anyone other than Moses or your sons, Aaron] who comes near shall be put to death.^(B)