레위기 13:8의 주석

וטמאו הכהן AND THE PRIEST SHALL PRONOUNCE HIM UNCLEAN — and as soon as he has pronounced him unclean he is a decided leper and he is obliged when he recovers from his leprosy to bring two birds (as a means of his purification) and to shave his flesh and to bring the offering which is mentioned in the section beginning זאת תהיה — Leviticus ch. 14 (cf. Megillah 8b).

צרעת הוא. it is a form of leprosy. The meaning of these words is that even if the priest had previously declared the person afflicted as "clean," this judgment is reversesd retroactively in light of the afflicted area having spread. The reason is that a scab which does not indicate ritual impurity is not in the habit of spreading. The Torah indicates that the spreading needs only to be minimal in order for the afflicted person to be declared as ritually impure. It is the scab which is the affliction, not its size.

צרעת היא, definitive, beyond doubt. The afflicted person has to remain in isolation until cured when he or she will offer bird-offerings.

And a sacrifice. I.e., this is not the case regarding a metzoro who is [only] confined, who does not have any of these. Because the impurity of a confined metzoro is mentioned here as well as the impurity of a metzoro who is definitely impure, as [we see that] “impurity” is mentioned with regard to both of them, as it is written concerning the confined one, “and he shall wash his clothing,” which implies that he is impure, and regarding the definitely impure it is written, “the kohein shall declare him unclean...” [Therefore,] Rashi here lets us know the difference between them as well.

צרעת היא, “it is the dreaded skin disease known as tzoraat.” What had first been diagnosed as נגע and had therefore been described in the masculine mode, is now described in the feminine mode, i.e. צרעת. (Compare verse 3)

צרעת הוא IT IS A LEPROSY — this מספחת is a leprosy (while the מספחת mentioned in v. 6 is a clean scab)

This. Rashi needs to explain this because מספחת (white discoloration) is the special name for a pure skin-eruption, [therefore,] he needs to explain that the word היא refers to the word המספחת, and its explanation is that the skineruption, which we would have thought is a מספחת and thus pure, is actually tzora’as and is impure. Above, however, concerning (v. 6): “מספחת היא (it is [merely] a white discoloration),” it surely refers to the word בהרת above, and since בהרת is a general expression for every brightly hued skin-eruption, it is fine to say, “מספחת היא,” that is, the mentioned above בהרת [is merely a white discoloration]. There, Rashi does not need to explain anything (Re’m).

The word צרעת is feminine; נגע is masculine.

is masculine. Rashi is answering the question: Above, it is written, “נגע צרעת הוא” [in the masculine form] which implies that tzora’as is masculine, but here it is written, “נגע צרעת כי תהיה,” which is the feminine form. For this reason Rashi explains: “Tzora’as is of feminine gender, but נגע is masculine.” Because of this, it is written above, “נגע צרעת הוא”; the word הוא refers to נגע which is masculine.