Leviticus 13:21-23

King James Version

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.