(Mishnah): What is later? It is after the time to get off the bed and clean the area (of her Ervah).

[If blood is found on her cloth] after this, the 24 hours apply to her, and it is not Metamei Bo'alah (the one who had Bi'ah with her);

R. Akiva says, it is Metamei Bo'alah.

Chachamim admit that if she finds a Kesem, she is Metamei Bo'alah.

(Gemara - R. Yosi bei R. Bun): This is not later. What is later? It is in order to stretch her hand and take the cloth from under the pillow. After this time, her husband is Tahor.

(R. Lazar citing Rav): Chachamim [in our Mishnah] hold like R. Meir [who is Metamei retroactively for Kesamim].

(R. Yochanan): It is truly Chachamim [the majority, who argue with R. Meir].

Question: What is the source to say so?

Answer (Talmidim citing R. Yochanan): We learn Rabanan from R. Akiva. Just like R. Akiva says [about one who sees blood] that she is Metamei Bo'alah and she is not confused about her count (she considers the day she saw to be her first day of Nidah), so Rabanan say [about a Kesem] that she is Metamei Bo'alah and she is not confused about her count.

(Mishnah): Every woman is Muchzekes to be Tehorah regarding her husband;

If a man returns from traveling, his wife is Muchzekes to be Tehorah.

(Beis Shamai): A woman needs two Edim (examination cloths) for every act of Bi'ah, or [she may re-use the same two Edim if] she has Bi'ah in front of a lamp (and checks them each time);

Beis Hillel say, two Edim suffice for the entire night.

(Gemara - Aba bar Yirmeyah Kahana citing Shmuel): Any woman who does not have a Veses, she is forbidden to her husband until she checks.

Question (Mishnah): Every woman is Muchzekes to be Tehorah regarding her husband.

Answer #1: He explains that [our Mishnah] refers to one who came from the road.

Objection: [The next clause of] our Mishnah teaches that if one returns from traveling, his wife is Muchzekes to be Tehorah!

Answer #2 (R. Bun bar Chiyah): [Shmuel discusses when] he came and found her awake.

Question (Beraisa): Whether he found her awake or he found her asleep [she is is Muchzekes to be Tehorah].

Answer (R. Ba): [In the Beraisa] he left her b'Chezkas Taharah. (Shmuel discusses when he left her b'Chezkas Temei'ah.)

Question: What Onah (Veses) do we give to her?

Answer (Reish Lakish): We give to her an average Onah of 30 days. (TAL TORAH, CHACHMAS BETZALEL (PISCHEI NIDAH) 15a Sof DH Emnam - Reish Lakish establishes our Mishnah to discuss a woman without a Veses.)

(R. Yochanan): I learn that even after three years she is permitted, but only for a woman who has a Veses.

(R. Avahu): This is if she delayed seven days after her Veses [so she could immerse after the seven days of Nidah finished].

Question: He should be concerned to say that she did not immerse!

Inference (R. Chaninah): This teaches that it is forbidden for a woman [who could become Tahor] to delay in her Tum'ah.

Question (Shmuel bar Aba): Is this even if we know that she gave birth?

Answer (R. Yosi): Do we say so even if she became Tamei?! (Surely we do not!) Rather, since she gave birth, her Chazakah [of Taharah] is Batel (and we do not rely on an assumption that she immersed). Also here, since she became Tamei, her Chazakah is Batel! (This is unlike R. Avahu. Rather, R. Yochanan does not discuss when we know that she became Tamei.)