Charles Ellicott Commentary Leviticus 13:15

"And the priest shall look on the raw flesh, and pronounce him unclean: the raw flesh is unclean: it is leprosy." — Leviticus 13:15 (ASV)

And the priest shall see the raw flesh. —Rather, the sound flesh. It will be seen that it is the sound flesh only, and not the white hair, which renders the patient unclean.