Leviticus 13:20 in the World English Bible
The priest shall examine it. Behold, if its appearance is deeper than the skin, and its hair has turned white, then the priest shall pronounce him unclean. It is the plague of leprosy. It has broken out in the boil.
Context
19 And in the place of the boil there be a white rising, or a bright spot, white, and somewhat reddish, and it be shewed 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: