Leviticus 13:21

¹⁹  And in the place of the boil there be a white rising, or a bright spot, white, and somewhat reddish, and it be showed to the priest;

²⁰  And if, when the priest seeth it, behold, it be in sight lower than the skin, and the hair thereof be turned white; the priest shall pronounce him unclean: it is a plague of leprosy broken out of the boil.

²¹  But if the priest look on it, and, behold, there be no white hairs therein, and if it be not lower than the skin, but be somewhat dark; then the priest shall shut him up seven days:

²²  And if it spread much abroad in the skin, then the priest shall pronounce him unclean: it is a plague.

²³  But if the bright spot stay in his place, and spread not, it is a burning boil; and the priest shall pronounce him clean.