Rashi on Leviticus 13:10/רש"י על ויקרא י״ג:י׳

1ומחית A QUICK [RAW FLESH] — sainement in old French English healing; — it means that the part of the white within the “higher-lying white spot” (השאת) has turned to a flesh-colour; this, too, is a symptom of uncleanness; — white hair without healthy flesh, and healthy flesh without white hair . Although healthy flesh is mentioned only in connection with a spot of higher-lying colour, in the case of all pure white colours (snow-white and wool-white) and their shades (lit., derivations) it is also a symptom of uncleanness(cf. Sifra, Tazria Parashat Nega'im, Section 3 1; Mishnah Negaim 4:6).