If there is any man among you who becomes unclean by some occurrence in the night, then he shall go outside the camp; he shall not come inside the camp.
Deuteronomy 23:10
Surrounding context
23:9 "When the army goes out against your enemies, then keep yourself from every wicked thing.
23:10 If there is any man among you who becomes unclean by some occurrence in the night, then he shall go outside the camp; he shall not come inside the camp.
23:11 But it shall be, when evening comes, that he shall wash with water; and when the sun sets, he may come into the camp.