Leviticus 13:4-5, 23

And if the bright spot be white in the skin of his flesh, and the appearance thereof be not deeper than the skin, and the hair thereof be not turned white, then the priest shall shut up him that hath the plague seven days: and the priest shall look on him the seventh day: and, behold, if in his eyes the plague be at a stay, and the plague be not spread in the skin, then the priest shall shut him up seven days more

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