As a general rule, with Tum'ah (impurity), any utensil—something like furniture or dishes, for example—could become tamei (impure). But if a utensil is broken and then loses its status, basically, as a utensil, it cannot become impure anymore. Here we'll talk about something called a Kisei shel kallah, a bridal chair, which is a decorated chair on which they would seat the bride at her wedding. If it was broken, how do we look at it in terms of the laws of Tum'ah? The Mishnah says: If there's a bridal chair with the armrests broken off, Beit Shammai says that it could become impure even though it has no armrests and a bride wouldn't normally use it anymore. Since it still could be used as a chair, it's not considered broken. It's still considered to be a chair. It can be a chair, and therefore it has the ability to become tamei. Beit Hillel says that the chair is tahor (pure). In other words, it cannot become tamei because it's not a keli, it's not a utensil, because it can't be used for its purpose. Its purpose originally was to have a bride sit in it. And if a bride can't sit in it anymore, even though it still could be sat in by anybody, it's still a chair, says Beit Shammai. Beit Hillel says that even the seat of a regular chair could become tamei on its own without the rest of the chair. If there's just the bottom square that someone can actually sit on, that's considered to be a chair. It has a purpose, and therefore a person could make the chair impure. Kal va-chomer, how much more so in our case of a Kisei shel kallah: it's a full, regular chair that's decorated, but it's just missing the armrests. Shammai would say, of course, that it could also become tamei.
The next part of the Mishnah will discuss a certain type of Tum'ah called Mishkav u'moshav, which tells us that certain people who are impure—a zav (man with a discharge), a zava (woman with a discharge), a nida (menstruant), or a yoledet, a woman who just gave birth—could make something they normally sit on impure, even if they don't actually touch it. For example, let's say they're lying down on a bed, and there's a cushion or covers on top of that bed, so they don't actually touch the bed, but they're lying on top of it. That's enough to make it tamei through Mishkav u'moshav. But only an item that's normally used to sit or lie on is considered able to become tamei with this type of Tum'ah. If a tamei person sits on a regular object that's not used, but he's not actually touching it—for example, if he's sitting on a cushion that's on it—he would not actually make it tamei. Of course, if somebody touched anything directly, they would make it impure. But here we're talking about a case where they never actually touched it.
So here the Mishnah is going to talk about a certain type of seat and whether it's considered to be a chair in terms of the Tum'ah of Mishkav u'moshav. There's a chair attached to the inside of a large kneading bowl, the kind they would have in those days. They would have this huge bowl that a person would actually go in, and they would put a chair in there. They wouldn't sit on the chair. The chair would be used as sort of a shelf to hold the dough. So that chair is in this kneading bowl. Beit Shammai says that the chair can become tamei if the person who's tamei is sitting on it, even though he's not touching it directly, as in the regular Mishkav u'moshav case, where he's sitting on a cushion on it, for example. Since it used to be a chair—it was a chair at one point in time—Beit Shammai says it does not lose its status, even though right now it's not a chair and it's attached to this kneading bowl. Beit Hillel says that the chair is automatically tahor. It cannot become tamei if a person who is tamei sits on it, Mishkav u'moshav, because now it's not considered to be a chair anymore. It's part of a kneading bowl, and therefore it is not subject to the Tum'ah of Mishkav u'moshav. Both of these are not considered to be a chair. Both Beit Shammai and Beit Hillel would agree, though, that if the chair is originally made as part of this kneading bowl, it's considered to be part of the bowl and not a chair, and therefore it can never become tamei. But Shammai would disagree: Shammai omer (Shammai says) that even a chair originally made as part of this kneading bowl is considered to be a chair in terms of Tum'ah. Even though it wasn't made to be a chair, since it can be used as a chair if a person wanted to, it is susceptible to Tum'ah. The discussion also addresses Tum'ah and the item's status as a chair.