Deuteronomy 23:12-14 NIV

12 Designate a place outside the camp where you can go to relieve yourself.
13 As part of your equipment have something to dig with, and when you relieve yourself, dig a hole and cover up your excrement.
14 For the LORD your God moves1 about in your camp to protect you and to deliver your enemies to you. Your camp must be holy,2 so that he will not see among you anything indecent and turn away from you

References for Deuteronomy 23:14