Leviticus 13:10-11

10The priest must look at the person. If the skin has a white mark and white hair on it, the person has a disease. If the mark has no skin on part of it, the person has a disease. But it may not be a disease that he could give to other people.

11The priest must say that the person is not clean. The priest need not keep him separate from the people. He already has a disease.