Charles Ellicott Commentary Leviticus 13:10

"and the priest shall look; and, behold, if there be a white rising in the skin, and it have turned the hair white, and there be quick raw flesh in the rising," — Leviticus 13:10 (ASV)

If the rising is white. —If the disease actually returns, one of two symptoms indicates it. A white rising will be noticed in the skin, which changes the black hair into white. The white hair only then indicates the disorder when it coexists with the white rising or swelling that produced it. If the original white swelling, which discoloured the hair, disappears, and a fresh white swelling forms itself around the existing white hair, it is no indication of uncleanness.

And there is quick raw flesh in the rising. —Rather, or if there is, or and likewise if there is, etc. This clause gives the second of the two symptoms, either of which indicates the return of the disorder. According to the administrators of the law during the Second Temple, the phrase here translated “quick raw flesh” in the Authorised Version, which literally means “the quickening of live flesh,” denotes “sound flesh,” or a spot in the flesh assuming the appearance of life after it had been paled by the whiteness that overspread the whole surface.

The size of this spot of live flesh, which indicated the disease and made the patient unclean, had to be at least that of a lentil. This rendering is given by the LXX, the Chaldee, etc. An isolated spot of sound flesh in the midst of a tubercle was considered a sign of the gnawing and consuming progress that the disease made in the surrounding flesh.