(Mishnah): She must check herself twice (morning and evening).

(R. Yosi bei R. Bun): This corresponding to the two times that the day changes for people (from day to night, and from night to day).

(R. Lazar citing R. Hoshayah): Wherever Chachamim said that her husband is obligated a Korban (she found blood within Shi'ur Vestah after Bi'ah, i.e. Osiyom), correspondingly, Taharos [that she touched, and within Shi'ur Vestah she saw blood] are Teluyos (Safek Teme'os. We neither eat nor burn them);

(Bar Padiyah): Whenever Chachamim said that her husband is Chayav Chatas, correspondingly Taharos are (fully) Teme'os (we burn them). Whenever her husband brings Asham Taluy (i.e. she found blood after Osiyom, but within the time it takes to descend from the bed and clean herself), correspondingly Taharos are Teluyos. Whenever her husband is exempt, correspondingly Taharos are Tehoros.

Question (R. Shmuel bar Rav Yitzchak, against R. Hoshayah): If an elder and a child were walking in a hall, is it not clear that the elder first uses (opens the door to leave), but the child can come right after him?! (This is a parable - if the Ever left first, and the blood right after, we assume that the blood was already there at the time that the Ever left, therefore he is Chayav Korban. For the same reason, Taharos should be Tamei!)

Answer (R. Avun citing R. Yudan): There (regarding her husband), there was Bi'ah; the Ever sealed the opening (we can say that the blood was already there, but could not leave until the Ever left). Here (Taharos), if the blood was already there [when she touched], what prevented it from leaving [immediately]?

Question (even against R. Hoshayah - Beraisa): If she separated [from the Taharos] and saw [blood], she is Tamei, and all of them are Tahor.

Question (against Bar Padiyah - Mishnah - R. Yehudah): [She must check herself] also when she finishes eating Terumah.

What is the reason [to check then]? Is it not that if she will see, [the Terumah] is Tamei retroactively?

Answer #1 (R. Ezra, to R. Mana): This discusses a woman without a Veses. (She has 24 hours of retroactive Tum'ah from when she sees.)

Objection (R. Mana): So said R. Yosi b'Ribi - our entire [Mishnah] here discusses a woman who has a Veses!

Answer (R. Yosi bei R. Bun): Until here, our Mishnah discusses a woman who has a Veses. From here and onwards, [it discusses] a woman without a Veses

Answer #2: You can even say that our Mishnah discusses a woman who has a Veses;

How will Bar Padiyah answer this? [Chachamim] argue with R. Yehudah (he holds like Chachamim).