Leviticus 13:2-3

2‘A person may have a kind of mark on his skin that might be a disease. He might give the disease to other people. If he has a mark like that, you must bring him to the priest.

3The priest must look at the mark. If the hair on the mark is white, it might be a disease. If the mark is under the skin and on the skin it might be a disease. The priest must say that the person is not clean.