Deuteronomy 23:9-14

Laws of Sanitation

⁹ When you are camped out, at war with your enemies, be careful to keep yourself from anything ritually defiling. ¹⁰ If one of your men has become ritually unclean because of a nocturnal emission, he must go outside the camp and stay there ¹¹ until evening when he can wash himself, returning to the camp at sunset. ¹² Mark out an area outside the camp where you can go to relieve yourselves. ¹³ Along with your weapons have a stick with you. After you relieve yourself, dig a hole with the stick and cover your excrement. ¹⁴ God, your God, strolls through your camp; he's present to deliver you and give you victory over your enemies. Keep your camp holy; don't permit anything indecent or offensive in God's eyes