Mishnayos Keilim Perek 19 Mishnah 4

נישא הזב על המטה ועל המיזרן (if the person with gonorrhea was carried on the bed and on the girth) – not exactly carried on the bed girth, but rather that the person with gonorrhea was carried on the bed that the girth is tied around it and extends from it.

מטמא שנים ופוסל אחד דברי ר' מאיר – Rabbi Meir according to his reason that he stated above (see previous Mishnah, Tractate Kelim, Chapter 19, Mishnah 3), that even if the bed birth extends from the bed a little bit, and even more, it is attached/connected to the bed, and the two are made impure and renders [the heave-offering] unit, like the bed itself. For all that the person with gonorrhea is carried upon and acts of lying and sitting are performed by the person with gonorrhea, which is a primary category of ritual impurity, and the person who touches is first degree [level of ritual impurity], and something that is first-degree [level of ritual impurity] makes something else second [degree level of ritual impurity] , and something that is second degree [level of ritual impurity] makes something third [degree level of ritual impurity] to invalidate the heave-offering/priest’s due alone, but not to make it impure. And this is where he defiles two degrees, which are first [degree of ritual impurity] and second [degree of ritual impurity] and he invalidates one and it is third [degree level of impurity] and it is invalid for heave offering alone. And the bed girth all the while that it was not removed from the bed is considered like a primary source of ritual impurity, and it defiles two and invalidates one, but after he removes it, it is nothing other than a derivative of the defilement which defiles one and invalidates one, according to the law of a person who touches that which the person with gonorrhea lies upon.

ר' יוסי אומר = Rabbi Yossi according to his reasoning, who stated above (in Tractate Kelim, Chapter 19, Mishnah 3) ten handbreadths and not further. Therefore, that which is within ten [handbreadths] is considered a connection/attachment to lying [by a person with gonorrhea], and it defiles two and invalidates one all the while that he did not remove it. But what is beyond ten [handbreadths] is not considered an attachment to the lying [by a person with gonorrhea], and its law is as it was explained, that it defiles one and invalidates one.

נישא על המזרן מעשרה ולפנים טמאה – this is our reading (i.e., טמאה). But we don’t have the reading of טמא/impure. And this is an explanation: if the person with gonorrhea was carried on the bed girth that extends from the bed, if he was carried from ten [handbreadths] and within to the side of the bed, the bed is impure through treading/Midras, for since all ten [handbreadths] are considered an attachment to the bed, but from ten [handbreadths] and beyond it is not an attachment/connection to the bed, and the bed is pure and its not defiled [with the defilement] of the bed girth. Such it appears in my eyes an explanation/commentary on this Mishnah. And the reading of my Teachers/Rabbis who have the [textual] reading "טמא וטהור" /impure and pure and their explanation, but it was not acceptable to me. And similarly the words of Maimonides who wrote in his commentary to this Mishnah did not enter my eyes are all. And I investigated afterwards in his work (i.e., the Mishneh Torah) in the Laws of Kelim/Vessels, Chapter 21 [Halakha 9] – it appears to me that there he retracted and explained this Mishnah as I explained it here.