Leviticus 20:25-26

You shall therefore distinguish between clean animals and unclean, between unclean birds and clean, and you shall not make yourselves abominable by beast or by bird, or by any kind of living thing that creeps on the ground, which I have separated from you as unclean. And you shall be holy to Me, for I the LORD am holy, and have separated you from the peoples, that you should be Mine.