Leviticus 13:18-23

“When a person has a boil and it heals and in place of the boil there is white swelling or a reddish-white shiny spot, the person must present himself to the priest for an examination. If it looks like it has penetrated the skin and the hair in it has turned white, the priest will pronounce him unclean. It is a serious skin disease that has broken out in the boil. But if the examination shows that there is no white hair in it and it is only skin deep and has faded, the priest will put him in quarantine for seven days. If it then spreads over the skin, the priest will diagnose him as unclean. It is infectious. But if the shiny spot has not changed and hasn’t spread, it’s only a scar from the boil. The priest will pronounce him clean.