Keilim, Chapter 26, Mishnah 2. This chapter is devoted to vessels fashioned from leather, and here the attention falls on the family of pouches and money bags that are shut by drawing a cord tight. One question runs through the whole discussion: does this piece of hide actually serve to hold something? If it does, it ranks as a kli and tumah can take hold of it. So we must examine what remains of the pouch when its cord has been disturbed, or when the hide has been opened out into a flat sheet.
A pouch whose cords were withdrawn
The Mishnah begins: "kis shel shenatzot shenitlu shenatzav, tamei" - a pouch closed by cords, whose cords were pulled out, is still subject to tumah. Even with the cord no longer in place, we continue to regard the hide as a receptacle, since threading the cord back through is a matter of a moment.
One might assume that this can only be the position of Rabbi Yose, who taught in the previous mishnah that drawing the cords out of their loops leaves the vessel intact. On closer look, though, the ruling here is acceptable even to the first tanna there. In our case the cords were slipped out of the loops but are still attached to the pouch itself, and in that situation the first tanna too would agree that the leather has not lost its standing as a container and can therefore contract tumah. What the first tanna ruled strictly about was leather whose cords were truly missing, so that it no longer served to hold anything. So long as the drawstring is there to close the pouch and give it the contours of a receptacle, tumah applies. Our mishnah is teaching that cords merely slipped free of their loops, while remaining fastened to the leather, do not take that standing away.
When the hide is opened out flat
"Nifshat, tahor" - should the pouch be spread apart until it is nothing but a flat piece of hide, it is tahor. When it lies open and not a trace of a cavity can be made out in it, all agree that it has ceased to be a kli and tumah does not apply, even if the cord is still fastened to it.
A patch attached at the bottom
"Tala alav et hamatlit milmatah, tamei" - if a patch was sewn onto the lower part of the pouch, tumah still applies to it. Here is why: the doubled area where the patch is fixed can never be pressed altogether smooth. A small hollow persists there in any case, so the leather never entirely surrenders the look of a receptacle, and it stays susceptible.
One pouch stitched inside another
"Kis betoch kis shenitma echad mehen bemashkeh, lo nitma chavero" - a small pouch was sewn inside a larger one, and then a liquid rendered one of them tamei. Its companion remains unaffected. The stitching that joins them does not merge them; halachah views each as a kli in its own right, so what befalls the one leaves nothing behind on the other.
The wrapping of a pearl
"Tzeror hamargalit, tamei" - the leather in which a pearl or precious stone is wrapped remains subject to tumah even once the stone has been taken out of it, because the hollow form is still there. Such a piece of hide is bound snugly about the stone so that it will hold fast, and the stone stays inside it for long periods. In consequence the leather sets into a curved, pouch-like shape and will not spring open again when it is emptied. Granted that it started out as a flat patch that was gathered around the stone and knotted shut, and granted that the string was undone when the stone was removed, still, the length of time it spent holding its contents has given it a permanent form, and it goes on serving as a receptacle.
The wrapping used for coins
"Tzeror hamaot, Rabbi Eliezer metamei vachachamim metaharin" - as for a leather wrapping in which money is kept, Rabbi Eliezer holds that tumah applies to it, while the Chachamim declare it tahor.
The reasoning of the Chachamim is that money is handled all the time. The wrapping is opened to take a coin out and knotted again when coins are put back, so it is never left closed around its contents long enough to harden into a pouch. With no settled hollow form to it, it is not a kli and tumah does not apply.
Rabbi Eliezer responds that there are times when a person knots such a wrapping firmly and leaves the coins undisturbed within it for a good while. Then the leather does acquire a fixed form, and it goes on functioning as a receptacle over the long run even after the coins are gone from it. That is why Rabbi Eliezer holds that tumah applies to the wrapping even once the money has been taken out.