But if the priest examines the scaly infection and it does not appear to be deeper than the skin, and there is no black hair in it, the priest shall isolate the infected person for seven days.
The priest is here instructed what judgment to make if there was any appearance of a leprosy, either, 1. In an old ulcer, or bile, that has been healed, Lev 13:18, etc. When old sores, that seemed to be cured, break out again, it is to be feared there is a leprosy in them; such is the danger of those who, having escaped the pollutions...
Commenting on Leviticus 13:18-37
And in the seventh day the priest shall look on the plague,.... To see whether it has got any deeper, or spread any further, and has any hair growing in it, and of what colour, that he might be also able to judge whether it was a leprosy or not: and, behold, if the scall spread not; was neither got into the flesh, nor larger...
Lev 13:29-31 Leprosy upon the head or chin. - If the priest saw a mole upon the head or chin of a man or woman, the appearance of which was deeper than the skin, and on which the hair was yellow (צהב golden, reddish, fox-colour) and thin, he was to regard it as נתק.
Commenting on Leviticus 13:29-31