Leviticus 13:20-22

New King James Version

²⁰ and if, when the priest sees it, it indeed appears deeper than the skin, and its hair has turned white, the priest shall pronounce him unclean. It is a leprous sore which has broken out of the boil. ²¹ But if the priest examines it, and indeed there are no white hairs in it, and it is not deeper than the skin, but has faded, then the priest shall isolate him seven days; ²² and if it should at all spread over the skin, then the priest shall pronounce him unclean. It is a ^[a]leprous sore.