Deuteronomy 23:12-14

¹² You shall have a designated area outside the camp to which you shall go. ¹³ With your utensils you shall have a trowel; when you relieve yourself outside, you shall dig a hole with it and then cover up your excrement. ¹⁴ Because the Lord your God travels along with your camp, to save you and to hand over your enemies to you, therefore your camp must be holy, so that he may not see anything indecent among you and turn away from you