Deuteronomy 23:9 in the World English Bible
When you go out and camp against your enemies, then you shall keep yourselves from every evil thing.
Context
8 The children that are begotten of them shall enter into the congregation of the LORD in their third generation.
9 When the host goeth forth against thine enemies, then keep thee from every wicked thing.
10 If there be among you any man, that is not clean by reason of uncleanness that chanceth him by night, then shall he go abroad out of the camp, he shall not come within the camp: