Numbers 3:7–8
7 They shall keep guard over him and over the whole congregation before the tent of meeting, ias they minister at the tabernacle. 8 They shall guard all the furnishings of the tent of meeting, and keep guard over the people of Israel as they minister at the tabernacle.
Numbers 18:7
7 And cyou and your sons with you shall guard your priesthood for all that concerns the altar and dthat is within the veil; and you shall serve. I give your priesthood as a gift,1 and eany outsider who comes near shall be put to death.”