Deuteronomy 23:10-14

10If one of your men is unclean because of a nocturnal emission, he is to go outside the camp and stay there.

11But as evening approaches he is to wash himself, and at sunset he may return to the camp.

12Designate a place outside the camp where you can go to relieve yourself.

13As part of your equipment have something to dig with, and when you relieve yourself, dig a hole and cover up your excrement.

14For the Lord your God moves about in your camp to protect you and to deliver your enemies to you. Your camp must be holy, so that he will not see among you anything indecent and turn away from you.