Deuteronomy 23:10
If there be any man that is unclean by the reason of uncleanness that chanceth him by night, let him go out of the host and not come in again,
Leviticus 15:16
"'If any man's seed depart from him in his sleep, he shall wash his flesh in water and be unclean until evening.
Numbers 5:2-3
"Command the children of Israel that they put out of the host all the lepers and all that have issues and all that are defiled upon the dead;
1 Corinthians 5:11-13
but now I write unto you that ye company not together. If any that is called a brother, be a fornicator, or covetous, or a worshipper of images, either a railer, either a drunkard, or an extortioner: with him that is such see that ye eat not.