Negaim 4:5 - 4:6

זוקקה לשער לבן ולפסיון (if [the streak/thread] subjects it [the bright spot] to [restrictions in respect to] white hair and spreading) – if there is in that thread a white hair, he is declared to be a definitive leper. Or if it spread near the thread at the end of a week, he is impure. But if there isn’t in the width of the thread two hairs but it has white hair he does not defile, for it is not considered from the plague. But if it spread near the thread and there isn’t in its width two hairs, it is considered like spreading far from the plague, and it requires like a split [Cilician] bean.

אבל לא למחיה – that even if here is in the width of the thread of two hairs, the quick flesh that is on it does not defile. For the quick flesh needs that will be encompassed in the middle of the plague like a fortress which is in the middle of the city.

מצרפן – and they are judged as one plague. But if one of them spread a little bit or a white hair was forthcoming on one of them, he is declared to be a definitive leper on both of them.

ואם לאו אימנן מצרפן – and they are judged as two plagues, but if one of them spread but the other one did not spread, he is declared to be a definitive leper on the one, and is shut up/isolated on the other. And the practical difference is that when he is declared to be pure, he is required to bring two sacrifices.

בהרת כגריס – but not the place of the quick flesh, that is nine lentils of the bright white spot on the skin, and one lentil of quick flesh, ten lentils among them all.

גריס – they are nine lentils, and the quick flesh is not less than a lentil. Wherever that we teach בהרת/the bright white spot on the skin (i.e., eventually one of the symptoms of leprosy), the same law applies to the rest of the appearances that are smooth or variegated.

והלכה המחיה – that the plague comes upon its place.

הלך שער לבן – that it fell off or changed to black/dark.

ר' שמעון מטהר – it refers to the quick flesh that disappeared.

שלא הפכתו בהרת – that the white hair preceded the bright white spot on the skin of the place of the quick flesh.

שלא הפכתו בהרת כגריס – that the white hair preceded the bright white spot on the skin like a split Cilician bean, for the place of the quick flesh was missing that of a Cilician bean, and here also, Rabbi Shimon does not dispute other than when the quick flesh disappears. But the Halakha is not according to Rabbi Shimon.