Deuteronomy 23:11-15

But it shall be, when evening cometh on, he shall wash himself with water: and when the sun is down, he shall come into the camp again.

Thou shalt have a place also without the camp, whither thou shalt go forth abroad:

And thou shalt have a paddle upon thy weapon; and it shall be, when thou wilt ease thyself abroad, thou shalt dig therewith, and shalt turn back and cover that which cometh from thee:

For the LORD thy God walketh in the midst of thy camp, to deliver thee, and to give up thine enemies before thee; therefore shall thy camp be holy: that he see no unclean thing in thee, and turn away from thee.

Thou shalt not deliver unto his master the servant which is escaped from his master unto thee: