Leviticus 13:30-37

30Then the priest shall see the plague: and, behold, if it is in sight deeper than the skin; and there is in it a yellow thin hair; then the priest shall pronounce him unclean: it is a dry scall, even a leprosy upon the head or beard. 31And if the priest shall look on the plague of the scall, and, behold, it is not in sight deeper than the skin, and no black hair in it; then the priest shall shut up him that hath the plague of the scall seven days: 32And in the seventh day the priest shall look on the plague: and, behold, if the scall spreadeth not, and there is in it no yellow hair, and the scall is not in sight deeper than the skin; 33He shall be shaven, but the scall shall he not shave; and the priest shall shut up him that hath the scall seven days more: 34And in the seventh day the priest shall look on the scall: and, behold, if the scall is not spread in the skin, nor is in sight deeper than the skin; then the priest shall pronounce him clean: and he shall wash his clothes, and be clean. 35But if the scall shall spread much in the skin after his cleansing; 36Then the priest shall look on him: and, behold, if the scall is spread in the skin, the priest shall not seek for yellow hair; he is unclean. 37But if the scall shall be in his sight at a stay, and there is black hair grown in it; the scall is healed, he is clean: and the priest shall pronounce him clean.