Deuteronomy 23:10
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: 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:
The verse concerns a man rendered ceremonially unclean by a nocturnal bodily emission. Such a man was required to go abroad out of the Israelite camp in the wilderness and not come within it, so that personal uncleanness was kept separated from the camp. The separation required uncleanness in the camp to be put outside it. He had to remain outside until evening and wash himself and his clothing before returning to the camp. The command belongs to broader instructions that also required refuse to be carried far from the camp and the area around the camp to be kept free of impurities, so that the camp and its surroundings would stay clean and uncontaminated.
These cleanliness rules served both religious and physical ends, for the people's physical and moral good and for sanitary purposes, illustrating strict standards of cleanliness. They teach that God's people must take cleanliness and sanitation seriously and keep their surroundings healthful. Neglect of sanitation can spread disease and bring sickness and premature death. By this standard, a tobacco user would have had to either leave the camp or give up tobacco. He could return only after cleansing the mouth of its residue.