Deuteronomy 23:9-13

“When you go out as an army against your enemies, you shall be on guard against every evil thing.

“If there is among you any man who is unclean because of a nocturnal emission, then he must go outside the camp; he may not reenter the camp.

But when evening approaches, he shall bathe himself with water, and at sundown he may reenter the camp.

“You shall also have a place allocated outside the camp, so that you may go out there to relieve yourself,

and you shall have a spade among your tools, and it shall be when you sit down outside, you shall dig with it and shall turn and cover up your excrement.