Deuteronomy 23:12

8The children of the third generation who are born to them may enter into the LORD’s assembly.

9When you go out and camp against your enemies, then you shall keep yourselves from every evil thing.

10If there is among you any man who is not clean by reason of that which happens to him by night, then shall he go outside of the camp. He shall not come within the camp;

11but it shall be, when evening comes, he shall bathe himself in water. When the sun is down, he shall come within the camp.

12You shall have a place also outside of the camp where you go relieve yourself.

13You shall have a trowel among your weapons. It shall be, when you relieve yourself, you shall dig with it, and shall turn back and cover your excrement;

14for the LORD your God walks in the middle of your camp, to deliver you, and to give up your enemies before you. Therefore your camp shall be holy, that he may not see an unclean thing in you, and turn away from you.

15You shall not deliver to his master a servant who has escaped from his master to you.

16He shall dwell with you, among you, in the place which he shall choose within one of your gates, where it pleases him best. You shall not oppress him.