Levítico 13:30

Behold, if it be in sight deeper. — Better, Behold, if its appearance is deeper. The first symptom of its existence is the same as usual — the depression of the affected spot.

And there be in it a yellow thin hair. — Whilst the symptom of leprosy in other parts of the body consisted of the hair turning white on the affected spot, in the case of this distemper breaking out on the head or chin it was indicated by the naturally black hair changing its colour into a golden appearance, and becoming short. According to the administrators of the law during the second Temple, the colour of the hair became like that of the new plumage of young pigeons after they have lost their first feathers, or, in other words, like the appearance of thin gold. By the “thin hair” those authorities who came in contact with the disorder understand small or short hair. Hence they laid down the following rule: The condition of the hair constituting one of the signs of leprosy is its becoming short; but if it be long, though it is as yellow as gold, it is no sign of uncleanness. Two yellow and short hairs, whether close to one another or far from each other, whether in the centre of the affected spot or on the edge thereof, — no matter whether the affection on the spot precedes the yellow hair, or the yellow hair precedes the affection on the spot, — are symptoms of uncleanness.

It is a dry scall, even a leprosy. — The ancient canons laid down by those authorities in the time of Christ who had the official treatment of this distemper define the word (nethek), which is translated “dry scall” by an affection on the head or chin, which causes the hair on those affected parts to fall off by the roots, so that the place of the hair is quite bare.