Ezra 2:62
"These sought their register among those that were reckoned by genealogy, but they were not found: therefore were they, as polluted, put from the priesthood."
Cross References (ranked by relevance)
Numbers 3:10
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 18:7
Therefore thou and thy sons with thee shall keep your priest’s office for everything 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.