'Clean and the Unclean' in the Bible

Its priests treat my law violently, and they profane my holy objects; they do not distinguish between holy object and what is unholy, or between the clean and the unclean. They do not teach the difference, and they hide their eyes from my Sabbaths, and [so] I am profaned in the midst of them.

They must teach My people the difference between the holy and the common, and explain to them the difference between the clean and the unclean.