Leviticus 13:3

13:3 The priest must then examine the infection on the skin of the body, and if the hair in the infection has turned white and the infection appears to be deeper than the skin of the body, then it is a diseased infection, so when the priest examines it he must pronounce the person unclean.

Leviticus 13:6

13:6 The priest must then examine it again on the seventh day, and if the infection has faded and has not spread on the skin, then the priest is to pronounce the person clean. It is a scab, so he must wash his clothes and be clean.