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 difference between holy and unholy, and between unclean and 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 the LORD, If thou shalt return, then will I bring thee again, and thou shalt stand before me: and if thou shalt separate the precious from the vile, thou shalt be as my mouth: let them return to thee; but return not thou to them.
Ezekiel 44:23
And they shall teach my people the difference between the holy and profane, and cause them to discern between the unclean and the clean.