Deuteronomy 23:10
When there is among you any man that is not clean by reason of uncleanness that chances by night, then he shall go abroad out of the camp; he shall not come within the camp.
Leviticus 15:16
And the man, when his seed shall go forth from him, then shall wash all his flesh in water and be unclean until the evening.
Numbers 5:2-3
Command the sons of Israel that they put out of the camp every leper and every one that has an issue and anyone who is defiled by the dead.
1 Corinthians 5:11-13
But now I have written unto you not to associate with anyone calling himself a brother if he is a fornicator or covetous or an idolater or a railer or a drunkard or an extortioner; with such a one do not even eat.