Deuteronomy 23:9-11

Darby Translation

⁹ When thou goest forth into camp against thine enemies, then keep thee from every evil thing.

¹⁰ If there be with thee a man that is not clean from what hath happened in the night, then shall he go outside the camp; he shall not come inside the camp;

¹¹ and it shall be, towards evening, he shall bathe in water: and at the going down of the sun he may come inside the camp.