Leviticus 13:4-5, 23

But if the bright spot is white on the skin of his body, and it does not appear to be deeper than the skin, and the hair on it has not turned white, then the priest shall isolate him who has the infection for seven days. The priest shall look at him on the seventh day, and if in his eyes the infection has not changed and the infection has not spread on the skin, then the priest shall isolate him for seven more days.

But if the bright spot remains in its place and does not spread, it is only the scar of the boil; and the priest shall pronounce him clean.