Deuteronomy 23:10
If there is someone among you who is impure because of some nocturnal emission, he must leave the camp; he may not reenter it immediately.
Leviticus 15:16
"'When a man has a seminal emission, he must bathe his whole body in water and be unclean until evening,
Numbers 5:2-3
"Command the Israelites to expel from the camp every leper, everyone who has a discharge, and whoever becomes defiled by a corpse.
1 Corinthians 5:11-13
But now I am writing to you not to associate with anyone who calls himself a Christian who is sexually immoral, or greedy, or an idolater, or verbally abusive, or a drunkard, or a swindler. Do not even eat with such a person.