Numbers 18:1-3

Living Bible

18 The Lord now spoke to Aaron: “You and your sons and your family are responsible for any desecration of the sanctuary,” he said, “and will be held liable for any impropriety in your priestly work.

^2-3 “Your kinsmen, the tribe of Levi, are your assistants; but only you and your sons may perform the sacred duties in the Tabernacle itself. The Levites must be careful not to touch any of the sacred articles or the altar, lest I destroy both them and you.