Numbers 1:51 "So when the tabernacle is to set out, the Levites shall take it down; and when the tabernacle encamps, the Levites shall set it up. But the layman who comes near shall be put to death.

Numbers 4:15 "When Aaron and his sons have finished covering the holy objects and all the furnishings of the sanctuary, when the camp is to set out, after that the sons of Kohath shall come to carry them, so that they will not touch the holy objects and die. These are the things in the tent of meeting which the sons of Kohath are to carry.

Numbers 18:7 "But you and your sons with you shall attend to your priesthood for everything concerning the altar and inside the veil, and you are to perform service. I am giving you the priesthood as a bestowed service, but the outsider who comes near shall be put to death." (NASB ©1995)