Leviticus 13:9

6 and the priest shall look on him again the seventh day; and, behold, if the plague be dim, and the plague hasn`t spread in the skin, then the priest shall pronounce him clean: it is a scab: and he shall wash his clothes, and be clean.

7 But if the scab spread abroad in the skin, after that he has showed himself to the priest for his cleansing, he shall show himself to the priest again:

8 and the priest shall look; and, behold, if the scab be spread in the skin, then the priest shall pronounce him unclean: it is leprosy.

9 When the plague of leprosy is in a man, then he shall be brought to the priest;

10 and the priest shall look; and, behold, if there be a white rising in the skin, and it have turned the hair white, and there be quick raw flesh in the rising,

11 it is an old leprosy in the skin of his flesh, and the priest shall pronounce him unclean: he shall not shut him up, for he is unclean.

12 If the leprosy break out abroad in the skin, and the leprosy cover all the skin of [him who has] the plague from his head even to his feet, as far as appears to the priest;