Ezra 2:62
These sought the register of their birth, and found none, therefore were they put from the priesthood.
Numbers 3:10
And thou shalt appoint Aaron and his sons to wait on their priests' office: and the stranger that cometh nigh shall die for it."
Leviticus 21:21-23
No man that is deformed of the seed of Aaron the priest, shall come nigh to offer the sacrifices of the LORD. If he have a deformity, he shall not preace to offer the bread of his God.
Numbers 16:39-40
And Eleazar the priest took the brazen censers which they that were burnt had offered, and beat them and fastened them upon the altar,
Numbers 18:7
And see that both thou and thy sons with thee take heed unto your priests' office, in all things that pertain unto the altar and within the veil. And see that ye serve, for I have given your priests' office unto you for a gift to do service: and the stranger that cometh nigh, shall die."
Ezekiel 44:10-14
No nor the Levites that are gone back from me, and have deceived the people of Israel with errors, going after their idols: therefore shall they bear their own wickedness.