Negaim, Chapter 11, Mishnah 1. With this chapter the Mishnah opens an entirely new subject: nigei begadim, the tzara'as that appears in a garment. Everything until now has dealt with the four forms of tzara'as that appear on a human being, nigei adam, and that material is now behind us, with the exception of Chapter 14, which will describe the taharah of the metzora himself.
The opening line states a broad rule and at once carves out an exception: "Kol habegadim mitamim benega'im chutz mishel akum" - clothing in general can contract the tumah of nega'im, but not a garment owned by a non-Jew. The Mishnah then addresses the case of a Jew who buys clothing from a non-Jew: such a garment is inspected "betchilah", meaning that the kohen relates to the mark as though this were its very first appearance.
Why the garment starts fresh
The Rav notes that this holds true even where the discoloration was already sitting on the fabric before the sale, while the cloth was still owned by the non-Jew. The logic is that the material itself was always fit to contract this tumah, chazi lanega'im; the one thing standing in the way was that the cloth lay in a non-Jew's ownership, and that ownership held the halachah back. What follows is that any stretch of time during which the mark rested on the garment under gentile ownership is simply disregarded and contributes nothing to the tally. From the moment the cloth belongs to a Jew and a kohen inspects it, the process starts over from the beginning.
A garment is not like a body
This should be contrasted with a case we met earlier in the tractate: a non-Jew who had a baheres on his skin while he was still a non-Jew, and who then converted, with the baheres still present. There the ruling is that the baheres is tahor and stays tahor. Why is a purchased garment treated differently?
The difference lies in what was lacking. A non-Jew's skin is simply not a place where the laws of nega'im operate; the mark on his flesh was never a candidate for tumah to begin with, and a spot that arose in a state of complete non-susceptibility remains tahor even after he becomes a Jew. A garment, by contrast, is a piece of inanimate material that always had the makings of a nega. Nothing was wrong with the spot itself. It was only the fact that a Jew did not own the cloth that kept the halachos of nega'im from taking hold at that time. Remove that single impediment, and the garment is examined like any other garment brought before a kohen.
The Tosfos Yom Tov on the language of "days"
The Tosfos Yom Tov finds the Rav's reference to days puzzling and remarks that he does not understand what days have to do with the matter here. His point is that until a kohen has actually viewed the garment and issued a ruling, whether hesger (quarantine) or hechlet (a definitive declaration of tumah), the mark has no halachic standing whatsoever. Counting only ever starts from the kohen's pronouncement. Should an owner keep the garment out of sight for a full month, nothing at all has been set in motion, and no tumah exists before a kohen examines it. Only after the cloth has passed into Jewish ownership and been presented to a kohen for inspection do we regard this as the first appearance of a nega in that garment.
Skins from the sea
The Mishnah now turns to materials that fall outside the parshah of nigei begadim altogether: "ve'oros hayam einam mitamim benega'im" - skins that come from the sea are not susceptible to nega'im. These are hides of aquatic creatures, fish, whales, sharks and the like. The Rav grounds this in the wording of the pasuk, "lapishtim uletzemer o ba'or": the Torah lists flax and wool alongside leather. Just as flax and wool are products of species that grow on dry land, min hagadol ba'aretz, so too the leather included in this parshah must come from a species that grows on dry land.
The remarkable ruling of attachment
And here the Mishnah adds something striking. If a person joined to such a sea-skin anything that grows on the land, "chiber lahem min hagadol ba'aretz", the skin does become susceptible to nega'im. The Rav describes the attachment as being made with two knots, that is, drawn through and tightened, and drawn through and tightened a second time. And the attached item may be minimal: "afilu chut, afilu meshicha", a mere thread or a length of cord, provided it is davar shemekabel tumah, an item that is capable of contracting tumah, not necessarily tumas nega'im in particular.
This is a wonderfully sharp halachah. The thread or cord that was tied on is itself of no relevance to the laws of nigei begadim. Nevertheless, because it establishes a connection to something that grows in the ground, that small attachment is enough to draw the sea-skin into the category of materials that the Torah's parshah addresses, and the hide that was previously outside the system entirely now becomes susceptible to nigei begadim.