Numbers 18:5-7 And you shall attend to the duties of the sanctuary and of the altar, so that wrath may not fall on the Israelites again.

BSB⁽ⁱ⁾ ⁵ And you shall attend to the duties of the sanctuary and of the altar, so that wrath may not fall on the Israelites again. ⁶ Behold, I Myself have selected your fellow Levites from the Israelites as a gift to you, dedicated to the LORD to perform the service for the Tent of Meeting. ⁷ But only you and your sons shall attend to your priesthood for everything concerning the altar and what is inside the veil, and you are to perform that service. I am giving you the work of the priesthood as a gift, but any outsider who comes near the sanctuary must be put to death.”