Leviticus 13:5-6
5 On the seventh day the priest is to examine him, and if he sees that the sore is unchanged and has not spread in the skin, he is to keep him in isolation another seven days.
6 On the seventh day the priest is to examine him again, and if the sore has faded and has not spread in the skin, the priest shall pronounce him clean; it is only a rash. The man must wash his clothes, and he will be clean.