If, however, the scaly outbreak spreads further on the skin after his cleansing,
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
But if the scall be in his sight at a stay,.... If in a few days, or in a short space of time after this, it should appear that the scall is at a full stop, and does not spread any further at all: and that there is black hair grown up therein; which is a sign of health and soundness, and so of purity...
Lev 13:35-36 But if the eruption spread even after his purification, the priest, on seeing this, was not to look for yellow hair. “He is unclean:” that is to say, he was to pronounce him unclean without searching for yellow hairs; the spread of the eruption was a sufficient proof of the leprosy.
Commenting on Leviticus 13:35-36