Numbers 3:10
So you shall appoint Aaron and his sons to carry out the duties of the priesthood; but any outsider who approaches the tabernacle must be put to death.”
Berean Standard Bible
And thou shalt appoint Aaron and his sons, and they shall wait on their priest’s office: and the stranger that cometh nigh shall be put to death.
You shall appoint Aaron and his sons, and they shall keep their priesthood, but the stranger who comes near shall be put to death.”