Leviticus 10:10
10 You are to ldistinguish between the holy and the common, and between the unclean and the clean,
Leviticus 20:25
25 uYou shall therefore separate the clean beast from the unclean, and the unclean bird from the clean. You shall not make yourselves detestable by beast or by bird or by anything with which the ground crawls, which I have set apart for you to hold unclean.