Deuteronomy 23:10
If there shall be among you any man that is not clean by reason of uncleanness that chanceth to him by night, then shall he go abroad out of the camp, he shall not come within the camp:
Leviticus 15:16
And if any man's seed of copulation shall go 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 hath an issue, and whoever is defiled by the dead:
1 Corinthians 5:11-13
But now I have written to you not to keep company, if any man that is called a brother is a lewd person, or covetous, or an idolater, or a railer, or a drunkard, or an extortioner: with such person no not to eat.