OPINIONS: Shmuel rules that a woman's Bedikah before relations is not sufficient to prevent her from becoming Tamei retroactively if she later sees Dam Nidah, because her Bedikah is rushed and she does not inspect thoroughly.

(a) The RA'AVAD proves from here that a woman is not required to check all of the folds and cracks during a routine, internal Bedikah of the seven clean days, nor during the Bedikah of Hefsek Taharah. Such a thorough Bedikah is necessary only in order to prevent her from retroactively being Metamei Taharos, and not for permitting her to her husband. The Gemara is saying that a woman who is in a rush is not careful to practice the extra-stringent Bedikah of Taharos, but only intends to perform a Bedikah that will permit her to her husband. Therefore, she does not check the folds and cracks.

(b) The RAMBAN asserts that even if we accept the Ra'avad's lenient ruling, we may accept it only with regard to the Bedikos of the seven clean days. A Hefsek Taharah, though, certainly requires a thorough, internal Bedikah.

(c) The Ra'avad quotes another opinion that requires the full Bedikah of folds and cracks for the seven clean days and for a Hefsek Taharah, but does not require a full Bedikah before relations, since that Bedikah is only required mid'Rabanan, for a woman who handles Taharos (Nidah 11b).

(d) The RASHBA strongly disagrees with the Ra'avad. He asserts that that an internal Bedikah always requires a check of all the folds and cracks. The Gemara is saying that a woman who is in a rush does not perform a proper Bedikah, and she therefore neglects to check all the folds and cracks. The TOSFOS HA'ROSH and RITVA also explain the Gemara in this way, and the Ramban himself rules that this is the Halachah. This is the conclusion of the other Poskim as well.

OPINIONS: The Mishnah (2a) gives an example of Dayah Sha'atah (she becomes Tamei only from now onwards) as follows. A woman was sitting on a couch handling Taharos. She came off of the couch and saw Dam Nidah. The Mishnah says that she is Tamei, and the Taharos she was handling are Tahor.

The Gemara here asks, why does the Mishnah add that she was sitting on a couch? What difference does it make where she was sitting? The Gemara answers that the Mishnah is teaching that the couch is also affected by the ruling of Dayah Sha'atah, because if the ruling in such a case would be that the woman is Tamei retroactively for the last twenty-four hours, then the couch would also be Tamei. This is because a Nidah is not only Metamei objects that she touches (Tum'as Maga), but also objects that she sits on, even indirectly (Tum'as Moshav). The Mishnah is teaching that in a case of retroactive Tum'ah, all Tum'os of a Nidah apply (except with regard to being prohibited to her husband).

The Gemara says that this supports the ruling of Ze'iri. Ze'iri states that the retroactive twenty-four hour period of Tum'as Nidah applies to both Tum'as Mishkav and Tum'as Moshav, so that if one touched the couch on which the woman sat, he and his clothing are Tamei.

TOSFOS (DH Mesaye'a Lei l'Ze'iri) asks that there is no mention in the Mishnah that the person and the clothes become Tamei! Why does the Gemara say that the Mishnah support Ze'iri's ruling?

The question of Tosfos is not clear, because the Mishnah does support the statement of Ze'iri regarding the fact that the woman's status of retroactive Tum'ah applies to all types of Tum'as Nidah.

What exactly is Tosfos' question?

(a) The MAHARAM explains that Tosfos is bothered with how we know that the person is Tamei along with his clothes. It is true that we see from the Mishnah that a couch which the Nidah encountered through Mishkav or Moshav within the last twenty-four hours is Tamei, as the same Tum'ah applies to both of them. It must be that the Mishnah is not referring only to Tum'as Maga, because the Mishnah should have said that she was handling Taharos and "touching vessels." The fact that it mentions a couch, which becomes Tamei through Mishkav and Moshav, clearly implies that Tum'as Mishkav and Tum'as Moshav also apply. However, we do not know that these Tum'os apply to the fullest degree -- as they do in the case of a definite Nidah -- and make a person who touches such a couch become Tamei along with his clothes! Accordingly, there is no proof to the statement of Ze'iri, who says that the person who touches the couch, as well as the clothes he is wearing, become Tamei.

The RASHBA and RAMBAN seem to give an answer to this question of Tosfos. They write that if the Mishnah's intention was to teach merely that the woman makes Taharos become Tamei because she touched them within twenty-four hours before she found blood, then it could have said simply that she was handling Taharos and saw Dam Nidah, making all the Taharos that she handled become Tamei. Why does the Mishnah need to mention what she was sitting on at the time that she handled the Taharos? That additional information shows that she causes Tum'ah through Mishkav and Moshav as well.

How, though, do we know that the Mishnah's intention is to teach that she causes a person who touches the couch to be Tamei, together with his clothes? Perhaps the Mishnah means that she makes only the couch Tamei, but not a person (and his clothes) who touches it! The answer is that if this is the intention of the Mishnah, then the Mishnah should not mention specifically a couch. A couch is the prototypical case of Mishkav and Moshav which makes a person and his clothes become Tamei! The Mishnah instead should mention that she was handling "vessels." It must be that the Mishnah's intention is to teach that even a person and his clothes become Tamei. This is support for Ze'iri, who says that the normal laws of Tum'as Nidah regarding Mishkav and Moshav apply to retroactive Tum'ah.

(b) The Maharam gives another possible explanation for Tosfos' question. According to his second explanation, the answer of the Rashba and the Ramban do not apply. The Gemara asks that the couch does not seem to be something that should become Tamei in a case of doubt. There is a rule that a "thing that does not have the knowledge to reply when asked" ("Ein Bo Da'as Lisha'el" -- see 4b) that might have become Tamei is deemed to be Tahor. Ze'iri states that in the case of the Mishnah, the woman's friends had carried her on the couch within the last twenty-four hours. Since her friends had held the couch in their hands, and they do have "knowledge to reply when asked," the couch is given their status and is therefore deemed to be Tamei.

Tosfos is asking that this explanation of Ze'iri, which is a novel approach in itself, is enough of a reason for the Mishnah to mention the case of a couch. How do we also know that a person who touches the couch is Tamei? Since the Mishnah's mention of the couch teaches us a different Halachah, we cannot use it as support for the statement of Ze'iri that the couch is Metamei a person and his clothes.

This question of Tosfos is very strong. Is there any way to explain the proof of the Gemara for Ze'iri's statement?

The CHOCHMAS BETZALEL answers that according to the Ramban and the Rashba, the only proof we have from the Mishnah is that the Nidah also causes Tum'as Mishkav and Moshav. The Gemara is not trying to prove that a person and his clothes become Tamei. The fact that her Tum'ah also causes a person who touches the couch to become Tamei, together with his clothes, is derived from a teaching later, in which Rava learns that Tum'as Mishkav and Moshav should apply during these twenty-four hours through a Kal v'Chomer. (Y. MONTROSE)