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. (Numbers 3:10)
The word here does not have the same meaning as in ch. 1:51, where it signifies a non-Levite. Here it includes the Levites; in fact it refers to them particularly. The Levites were not allowed to intrude upon the special sphere of Aaron and his sons. Violation of this divine injunction was one of the sins of Jeroboam, who permitted non-Levites to perform priestly functions (see 1 Kings 12:25-33).
Cometh nigh.
These words do not mean to approach physically, in the ordinary sense, but to come to perform any of the sacred duties of the priesthood.