Leviticus 15:7
And he that toucheth the flesh of him that hath the issue shall wash his clothes, and bathe himself in water, and be unclean until the even. And he that toucheth the flesh of him that hath the issue shall wash his clothes, and bathe himself in water, and be unclean until the even.
Touching the flesh of one who has a discharge brings ceremonial uncleanness lasting until evening, requiring washing of clothing and bathing of the body in water. Contact with a bodily discharge or with a contaminating disease carries that same requirement of washed clothes and a bathed body. The one thus made unclean was to stay outside the camp until evening and to cleanse himself and his clothing before coming back into the camp. The broader provision for personal uncleanness likewise called for leaving the camp until evening and then cleansing self and clothing before return.
The requirement displays the thoroughness of the regulations governing contact with contaminating conditions. These washings and separations until evening formed part of the precautions against the spread of disease. The rule made personal cleanliness part of camp sanitation, teaching that God required His people to keep themselves and their surroundings free of impurity. It served both religious and sanitary purposes, since cleanliness helped prevent disease.