Leviticus 13:9-17

“Anyone who develops a serious skin disease must go to the priest for an examination. If the priest finds a white swelling on the skin, and some hair on the spot has turned white, and there is an open sore in the affected area, it is a chronic skin disease, and the priest must pronounce the person ceremonially unclean. In such cases the person need not be quarantined, for it is obvious that the skin is defiled by the disease. “Now suppose the disease has spread all over the person’s skin, covering the body from head to foot. When the priest examines the infected person and finds that the disease covers the entire body, he will pronounce the person ceremonially clean. Since the skin has turned completely white, the person is clean. But if any open sores appear, the infected person will be pronounced ceremonially unclean. The priest must make this pronouncement as soon as he sees an open sore, since open sores indicate the presence of a skin disease. However, if the open sores heal and turn white like the rest of the skin, the person must return to the priest for another examination. If the affected areas have indeed turned white, the priest will then pronounce the person ceremonially clean by declaring, ‘You are clean!’