Leviticus 13:1-14

Then the LORD spoke to Moses and to Aaron, saying, “When someone has on the skin of his body a swelling, or a scab, or a bright spot, and it becomes an infection of leprosy on the skin of his body, then he shall be brought to Aaron the priest or to one of his sons the priests. The priest shall look at the infected area on the skin of the body, and if the hair in the infection has turned white and the infection appears to be deeper than the skin of his body, it is an infection of leprosy; when the priest has looked at him, he shall pronounce him unclean. But if the bright spot is white on the skin of his body, and it does not appear to be deeper than the skin, and the hair on it has not turned white, then the priest shall isolate the person who has the infection for seven days. Then the priest shall look at him on the seventh day, and if in his eyes the infection has not changed and the infection has not spread on the skin, then the priest shall isolate him for seven more days. The priest shall then look at him again on the seventh day, and if the infected area has faded and the infection has not spread on the skin, then the priest shall pronounce him clean; it is only a rash. And he shall wash his clothes and be clean. “But if the rash spreads farther on the skin after he has shown himself to the priest for his cleansing, he shall appear again to the priest. And the priest shall look, and if the rash has spread on the skin, then the priest shall pronounce him unclean; it is leprosy. “When the infection of leprosy is on someone, then he shall be brought to the priest. The priest shall then look, and if there is a white swelling on the skin, and it has turned the hair white, and there is new raw flesh in the swelling, it is a chronic leprosy on the skin of his body, and the priest shall pronounce him unclean; he shall not isolate him, for he is unclean. If the leprosy breaks out farther on the skin, and the leprosy covers all the skin of the person who has the infection from his head even to his feet, as far as the priest can see, then the priest shall look, and behold, if the leprosy has covered his entire body, he shall pronounce the one who has the infection clean; it has all turned white and he is clean. But whenever raw flesh appears on him, he shall be unclean.