Leviticus 13:21-23

13:21 If, however, the priest examines it, and there is no white hair in it, it is not deeper than the skin, and it has faded, then the priest is to quarantine him for seven days. 13:22 If it is spreading further on the skin, then the priest is to pronounce him unclean. It is an infection. 13:23 But if the bright spot stays in its place and has not spread, it is the scar of the boil, so the priest is to pronounce him clean.