Leviticus 13:5-6

And the priest shall examine him on the seventh day; and indeed if the sore appears to be as it was, and the sore has not spread on the skin, then the priest shall isolate him another seven days. Then the priest shall examine him again on the seventh day; and indeed if the sore has faded, and the sore has not spread on the skin, then the priest shall pronounce him clean; it is only a scab, and he shall wash his clothes and be clean.