Nehemiah 7:64
These sought their register among those that were reckoned by genealogy, but it was not found: therefore were they, as polluted, put from the priesthood. These sought their register among those that were reckoned by genealogy, but it was not found: therefore were they, as polluted, put from the priesthood.
Those who claimed priestly descent had to prove their ancestry from the genealogical register, with eligibility for priestly service established by what was recorded there. Some sought their register among those reckoned by genealogy, but their names were missing and could not be found there. Where priestly ancestry could not be established or verified, the claim was not accepted. Those whose family register could not be found were therefore barred, excluded, and put from the priesthood.
They were put from the priesthood as polluted, meaning unclean and ceremonially defiled. The requirement shows the importance of proving one's place within Israel's recorded families before exercising the priest's office.