Leviticus 13:7-9

New International Version - UK

⁷ But if the rash does spread in their skin after they have shown themselves to the priest to be pronounced clean, they must appear before the priest again. ⁸ The priest is to examine that person, and if the rash has spread in the skin, he shall pronounce them unclean; it is a defiling skin disease.

⁹ ‘When anyone has a defiling skin disease, they must be brought to the priest.