Leviticus 13:24-28

24“When someone has a burn on their skin and a reddish-white or white spot appears in the raw flesh of the burn,

25the priest is to examine the spot, and if the hair in it has turned white, and it appears to be more than skin deep, it is a defiling disease that has broken out in the burn. The priest shall pronounce them unclean; it is a defiling skin disease.

26But if the priest examines it and there is no white hair in the spot and if it is not more than skin deep and has faded, then the priest is to isolate them for seven days.

27On the seventh day the priest is to examine that person, and if it is spreading in the skin, the priest shall pronounce them unclean; it is a defiling skin disease.

28If, however, the spot is unchanged and has not spread in the skin but has faded, it is a swelling from the burn, and the priest shall pronounce them clean; it is only a scar from the burn.