Leviticus 13:4, 5, 23

If the shiny spot on the skin is white but does not appear to be more than skin deep and the hair in it has not turned white, the priest is to isolate the affected person for seven days.

On the seventh day the priest is to examine them, and if he sees that the sore is unchanged and has not spread in the skin, he is to isolate them for another seven days.

But if the spot is unchanged and has not spread, it is only a scar from the boil, and the priest shall pronounce them clean.