Deuteronomy 23:12-14

Complete Jewish Bible

^12 (11) When evening arrives he is to bathe himself in water, and after sunset he may enter the camp. ^13 (12) Also you are to have an area outside the camp to use as a latrine. ^14 (13) You must include a trowel with your equipment, and when you relieve yourself, you are to dig a hole first and afterwards cover your excrement.