Leviticus 13:4-6

4“If it is a white bright spot on the skin of his body, but it does not appear to be deeper than the skin, and the hair has not turned white, then the priest is to quarantine the person with the infection for seven days.

5The priest must then examine it on the seventh day, and if, as far as he can see, the infection has stayed the same and has not spread on the skin, then the priest is to quarantine the person for another seven days.

6The 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.