Charles Ellicott Commentary Leviticus 13:39

"then the priest shall look; and, behold, if the bright spots in the skin of their flesh be of a dull white, it is a tetter, it hath broken out in the skin; he is clean." — Leviticus 13:39 (ASV)

Then the priest shall look. —If the priest, upon examination, finds that these elevated spots are of a dull or palish white colour, then he is to pronounce the patient clean, that is, free of leprosy, since it is simply a white eruption or benign skin rash, which lasts for a few months, causes no inconvenience, and gradually disappears of itself. Therefore, it is called bahack, or “white scaling,” and not leprosy. This nameless disorder, which still persists in the East, is still today called by the Biblical name bahack.