is it necessary to teach that an examination reduces the time from examination to examination, which is less than twenty-four hours?

The Gemara answers: This ruling is necessary, lest you say that with regard to the significant passage of a twenty-four-hour period the Sages are concerned for the possible loss of ritually pure items, but with regard to the smaller period from examination to examination, the Sages are not concerned for the loss of pure items, and therefore the use of an examination cloth should not reduce the time of possible impurity between that and her next examination. Therefore, the mishna teaches us that it does reduce this time.

§ The mishna teaches with regard to a woman who has a fixed menstrual cycle: Her time is sufficient, how so? If the woman was sitting in a bed and engaged in handling ritually pure items, and she left the bed and saw blood, she is impure and those items are pure. The Gemara asks: Why do I need the mishna to teach: If the woman was sitting in a bed and engaged in handling pure items? Let the mishna teach the same ruling without mentioning the bed: If she was engaged in handling pure items and she left and saw blood. The detail that she was sitting in a bed is apparently superfluous.

The Gemara answers: This detail teaches us that the reason why the bed is not rendered impure is that her time is sufficient and there is no retroactive impurity. It can be inferred that in a case where she is impure retroactively for a twenty-four-hour period, her bed is also rendered impure. This supports the opinion of Ze’eiri, as Ze’eiri said: The level of impurity of the retroactive twenty-four-hour period of a menstruating woman renders impure a bed upon which she lies and a chair upon which she sits, to the extent that they transmit impurity to a person who comes in contact with them, to the extent that he transmits impurity to the garments he is wearing.

This Gemara raises a difficulty: Now, this bed upon which she sat is an entity that lacks consciousness in order for it to be asked, and the principle with regard to any entity that lacks consciousness in order for it to be asked is that the item with uncertain status is deemed pure. The Gemara explains: Ze’eiri interpreted his ruling as applying specifically to a case where her friends are carrying her in the bed, where the bed is considered as the extended hand of her friends. In other words, it is part of an entity that has consciousness in order for it to be asked, and therefore the item with uncertain status is deemed impure.

The Gemara provides another answer: And now that Rabbi Yoḥanan said: In a case of uncertain ritual impurity that comes about by the hand of a person, i.e., through his involvement, the owner of the vessel must consult a Sage about it, i.e., it is considered an entity that has consciousness in order for it to be asked, as in such a case even with regard to a vessel that is placed upon the ground, which is certainly incapable of providing an answer if asked, its halakhic status is like that of an item that has consciousness in order for it to be asked. With this statement in mind, one can explain that according to Ze’eiri a menstruating woman transmits impurity to a bed even though her friends are not carrying her in the bed. Rather, as the bed’s ritual impurity was caused by the hand of a person, it has the halakhic status of an item that has consciousness in order for it to be asked.

§ The Gemara discusses the matter of Rabbi Yoḥanan’s statement itself. Rabbi Yoḥanan says: In a case of uncertain ritual impurity that comes about by the hand of man, its owner must consult a Sage about it, i.e., it is ritually impure, as in such a case even with regard to a vessel that is placed upon the ground, its halakhic status is like that of an item that has consciousness in order for it to be asked.

The Gemara raises an objection from a baraita (Tosefta, Teharot 4:1): If a man who contracted ritual impurity was wrapping himself in his cloak and there were pure items beside him; or if he was pure and there were impure items beside him as he was wrapping his cloak; or if there were pure items and impure items above his head at the time and there is uncertainty whether he touched the impure items with his cloak and then touched the pure items with his cloak, and uncertainty whether it did not touch them, the halakha is that the pure items remain pure. But if it is impossible for him to have wrapped himself unless his cloak had touched the impure items in the process, then those previously pure items become impure.

The baraita continues: Rabban Shimon ben Gamliel says that we say to him: Repeat your action. And he repeats the action of wrapping himself with his cloak, and it can then be determined whether or not the cloak and the other items came in contact with each other. The Rabbis said to him: We do not rely on repeated actions with regard to the determination of ritually pure items. Since the second action may not exactly mimic the first, it cannot be relied upon to determine ritual purity status.

The Gemara explains the objection: But according to the Rabbis, why is the halakha that the items in question remain pure? Isn’t this a case of uncertain ritual impurity that comes about by the hand of man, which, according to Rabbi Yoḥanan, is considered as having consciousness in order for it to be asked? If so, these items should be ritually impure.

The Gemara answers: Except for that one, i.e., do not raise a difficulty from that baraita, since it is referring to a specific case. As Rav Hoshaya teaches with regard to an item whose purity status is uncertain: When it is in the private domain, the item with uncertain status is deemed impure; when it is in the public domain, it is deemed pure. The baraita is referring to an item located in the public domain. Consequently, even if it is considered as having consciousness in order to be asked, nevertheless it is pure, as its uncertainty occurred in the public domain.

§ The Gemara analyzes the matter of Ze’eiri’s ruling itself. Ze’eiri says: The level of impurity assumed during the retroactive twenty-four-hour period of a menstruating woman renders a bed upon which she lies and a chair upon which she sits impure to the extent that they transmit impurity to a person who comes in contact with them to the extent that he transmits impurity to the garments he is wearing.

The Gemara asks: Is that so? But when Avimi came from Bei Ḥozai, he came and brought the following baraita with him: The level of impurity during the retroactive twenty-four-hour period of a menstruating woman renders her bed upon which she lies and her chair upon which she sits impure like the impurity level caused by her touch. The Gemara explains the difficulty: What, is it not correct to say that this means that just as an item rendered impure by her touch does not render another person impure, so too, her bed does not render another person impure?

Rava says: And how can you understand it in that manner? There is an a fortiori inference here: And if an earthenware vessel sealed with a tightly bound cover, which is spared from impurity when it is in a tent that has a corpse in it, is nevertheless not spared from impurity if the woman moved it during the twenty-four-hour period of retroactive impurity of a menstruating woman and is impure as though she moved it after she experienced bleeding; so too, with regard to beds and chairs, which are not spared from impurity in a tent that has a corpse in it, is it not logical that they are also not spared from impurity when used during the twenty-four-hour period of retroactive impurity of a menstruating woman and are impure as though she used them after she experienced bleeding?

The Gemara asks: But Avimi from Bei Ḥozai cited a baraita that apparently does not accept Rava’s a fortiori inference. The Gemara answers: One can say that the baraita does not mean that her bed and chair are rendered impure with the light level of impurity caused by her touch, but rather: Her bed upon which she lies and her chair upon which she sits