Leviticus 14:57
to teach when it is unclean, and when it is clean: this is the law of leprosy.
Leviticus 10:10
and that ye may make a distinction between the holy and the common, and between the unclean and the clean;
Deuteronomy 24:8
Take heed in the plague of leprosy, that thou observe diligently, and do according to all that the priests the Levites shall teach you: as I commanded them, so ye shall observe to do.
Jeremiah 15:19
Therefore thus saith Jehovah, If thou return, then will I bring thee again, that thou mayest stand before me; and if thou take forth the precious from the vile, thou shalt be as my mouth: they shall return unto thee, but thou shalt not return unto them.
Ezekiel 44:23
And they shall teach my people the difference between the holy and the common, and cause them to discern between the unclean and the clean.