Deuteronomy 23:10-15

10If any man among you becomes unclean because of a nocturnal emission, he must leave the camp and stay outside. 11When evening approaches, he must wash with water, and when the sun sets he may return to the camp.

12You must have a place outside the camp to go and relieve yourself. 13And you must have a digging tool in your equipment so that when you relieve yourself you can dig a hole and cover up your excrement.

14For the LORD your God walks throughout your camp to protect you and deliver your enemies to you. Your camp must be holy, lest He see anything unclean among you and turn away from you.

15Do not return a slave to his master if he has taken refuge with you.