Ezra 2:62

These searched among their ancestral registration, but they could not be located; therefore they were considered unclean and excluded from the priesthood.

Numbers 3:10

So you shall appoint Aaron and his sons that they may keep their priesthood, but the layman who comes near shall be put to death.”

Leviticus 21:21-23

No man among the descendants of Aaron the priest who has a defect is to come near to offer the Lord’s offerings by fire; since he has a defect, he shall not come near to offer the food of his God.

Numbers 16:39-40

So Eleazar the priest took the bronze censers which the men who were burned had offered, and they hammered them out as a plating for the altar,

Numbers 18:7

But you and your sons with you shall attend to your priesthood for everything concerning the altar and inside the veil, and you are to perform service. I am giving you the priesthood as a bestowed service, but the outsider who comes near shall be put to death.”

Ezekiel 44:10-14

But the Levites who went far from Me when Israel went astray, who went astray from Me after their idols, shall bear the punishment for their iniquity.

Treasury of Scripture Knowledge

Summary

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.

Were they, as polluted, put from the priesthood

Bible References

Therefore

Leviticus 21:21
No man among the descendants of Aaron the priest who has a defect is to come near to offer the Lord’s offerings by fire; since he has a defect, he shall not come near to offer the food of his God.
Numbers 3:10
So you shall appoint Aaron and his sons that they may keep their priesthood, but the layman who comes near shall be put to death.”
Numbers 16:40
as a reminder to the sons of Israel that no layman who is not of the descendants of Aaron should come near to burn incense before the Lord; so that he will not become like Korah and his company—just as the Lord had spoken to him through Moses.
Numbers 18:7
But you and your sons with you shall attend to your priesthood for everything concerning the altar and inside the veil, and you are to perform service. I am giving you the priesthood as a bestowed service, but the outsider who comes near shall be put to death.”

Were they, as polluted, put from the priesthood

Ezekiel 44:10
But the Levites who went far from Me when Israel went astray, who went astray from Me after their idols, shall bear the punishment for their iniquity.