Numbers 3:38

3:38 But those who were to camp in front of the tabernacle on the east, in front of the tent of meeting, were Moses, Aaron, and his sons. They were responsible for the needs of the sanctuary and for the needs of the Israelites, but the unauthorized person who approached was to be put to death.

Numbers 18:7

18:7 But you and your sons with you are responsible for your priestly duties, for everything at the altar and within the curtain. And you must serve. I give you the priesthood as a gift for service; but the unauthorized person who approaches must be put to death.”

Numbers 31:30

31:30 From the Israelites’ half-share you are to take one portion out of fifty of the people, the cattle, the donkeys, and the sheep – from every kind of animal – and you are to give them to the Levites, who are responsible for the care of the Lord’s tabernacle.”