Deuteronomy 23:10
If there be among you any man, that is unclean by reason of some occurrence in the night, then shall he go outside the camp, he shall not come inside the camp:
Leviticus 15:16
And if any man's semen go out from him, then he shall wash all his flesh in water, and be unclean until the evening.
Numbers 5:2-3
Command the children of Israel, that they put out of the camp every leper, and every one that has a discharge, and whosoever is defiled by the dead:
1 Corinthians 5:11-13
But now I have written unto you not to keep company, if any man that is called a brother be a fornicator, or covetous, or an idolater, or a railer, or a drunkard, or an extortioner; with such a one no not to eat.