Levítico 13:43

Then the priest shall look. — It is then the duty of the priest to ascertain whether the white-reddish rising in the bald backhead or bald forehead is in appearance like the leprosy in the skin of the flesh described in Levítico 13:2, excepting, of course, the white hair, which in this case could not exist.

As the leprosy appeareth in the skin of the flesh. — Better, in appearance like the leprosy in the skin of the flesh. Though the reddish-white eruption is the only symptom mentioned whereby head-leprosy is to be recognised, and nothing is said about remanding the patient if the distemper should appear doubtful, as in the other cases of leprosy, yet because it is here said “in appearance like the leprosy in the skin of the flesh,” the administrators of the law during the second Temple inferred that all the criteria specified in one are implied in the other. They interpret this phrase, “they are, and therefore must be treated like, leprosy in the skin of the flesh.” Hence they submit that there are two symptoms which render baldness in the front or at the back of the head unclean: viz., (1) live or sound flesh; and (2) spreading. “If live or sound flesh is found in the bright spot on the baldness at the back or in the front of the head, he is pronounced unclean; if there is no live flesh, he is shut up, and examined at the end of the week, and if live flesh has developed itself, and it has spread, he is declared unclean, and if not, he is shut up for another week. If it spreads during this time, or engenders live flesh, he is declared unclean, and if not, he is declared clean. He is also pronounced unclean if it spreads or engenders sound flesh after he has been declared clean.” Of course, the fact that the distemper in this instance develops itself on baldness precludes white hair being among the criteria indicating uncleanness.