וְאֶת־עַמִּ֣י יוֹר֔וּ בֵּ֥ין קֹ֖דֶשׁ לְחֹ֑ל וּבֵין־טָמֵ֥א לְטָה֖וֹר יוֹדִעֻֽם׃
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.
Read midrashic interpretation of Ezekiel 44:23: and classical rabbinic exegesis.