Numbers 18:7

And you and your sons after you shall keep up your priestly ministration, according to the whole manner of the altar, and that which is within the veil; and you⌃ shall minister in the services as the office of your priesthood; and the stranger that comes near shall die.

Therefore thou and thy sons with thee shall keep your priest’s office for every thing of the altar, and within the vail; and ye shall serve: I have given your priest’s office unto you as a service of gift: and the stranger that cometh nigh shall be put to death.

You and your sons with you shall keep your priesthood for everything of the altar, and for that within the veil. You shall serve. I give you the service of the priesthood as a gift. The stranger who comes near shall be put to death.”