Explanation: With difficulty they permitted to distance Chafifah so much [from Tevilah], only because if she does Chafifah on Leil (the night of) Tevilah, perhaps she will not do it well. Since she is anxious to be with her husband, she rushes to immerse.

Explanation #1 (Rashi): "This is when it is possible" to do Chafifah during the day, e.g. on a weekday. She does Chafifah during the day and immerses at night;

"This is when it is not possible" to do Chafifah during the day, e.g. when Tevilah is on Motza'ei Shabbos. If she does Chafifah on Erev Shabbos, it is distanced too much from Tevilah. [Rather,] she does Chafifah on Leil Tevilah, on Motza'ei Shabbos.

Question: This that we ruled above (67b) that the Halachah follows Rav Chisda, like Rav Yemar answered, does not persist, for here we say that she may not do Chafifah on Erev Shabbos and immerse on Motza'ei Shabbos!

Answer: We can establish the ruling above when Leil Tevilah is Motza'ei Shabbos, and it is Yom Tov. Surely she does Chafifah on Erev Shabbos, and she does not lose her Onah (Leil Tevilah, a time for intimacy), since she cannot do Chafifah on Leil Tevilah, and not the day before Leil Tevilah.

Remark: In any case, according to Rashi it seems that Chafifah on Leil Tevilah is permitted, just it is better that she do Chafifah during the day, for [at night] she rushes to be with her husband.

Support #1: [The Gemara] connotes like this. It says that a woman does Chafifah during the day. It does not say that she may do Chafifah only during the day, like [the other ruling] says "she may do Chafifah only at night."

Support #2: Above, in the episode in the Reish Galusa's house, it connotes that Chafifah on Leil Tevilah is permitted;

It is unreasonable to distinguish that [it was permitted only] because they quarreled, for we bring from that episode that a Nidah may do Chafifah at night. This connotes even without Ones!

Explanation #2: The She'altos of Rav Achai (Acherei Mos 96) explained "this is when it is possible" to do Chafifah on Leil Tevilah, when [the night] is a Yom Chol. She should not distance Chafifah from Tevilah at all, even if also the day was Chol. She does Chafifah only at night;

"This is when it is not possible", e.g. Leil Tevilah is Yom Tov or Shabbos. Then she does Chafifah during the day before the Tevilah;

Even if the day before the Tevilah is also Yom Tov or Shabbos, then she does Chafifah on Erev Shabbos or Erev Yom Tov like the ruling above, that Mereimar expounded that the Halachah follows Rav Chisda, like Rav Yemar answered.

Consequence: According to the She'altos, whenever possible she should do Chafifah only on Leil Tevilah.

Distinction: However, according to the custom of women nowadays, that they delay in the bathhouse until the night, it is permitted even according to the She'altos;

He forbids only to do Chafifah during the day and leave the bathhouse before night. However, if she stays there until night, it is a long Chafifah. As long as she engages in Chafifah of her body and hair, she should be blessed!

Remark: Also, some women are stringent, that even though she does Chafifah, they take a comb and comb themselves in the place where they immerse.

Explanation #3 (R. Tam): "You should be astounded at yourself!' is a repetition (of what was said. His next words do not object to every case of Chafifah during the day and Tevilah at night, rather, only the case just mentioned.) I.e. how can you say so, that a woman does Chafifah during the day (on Erev Shabbos) and immerses at night on Motza'ei Shabbos? (This is wrong.) We require Samuch l'Chafifah Tevilah!

Objection (Ri): We find like this [expression] in Pesachim (23a) "you should be astounded at yourself! How is Chametz Asur b'Hana'ah all seven days?" (This begins a Beraisa there. It means "you cannot say the following." We can say so also here!)

Note: Aruch l'Ner says that the coming Diburim DH v'Hilchesa and DH Ha are continuations of R. Tam's opinion. They appear like separate Diburim due to a printing mistake.

Explanation #3 (cont.): [The Halachah is that] She does Chafifah on Erev Shabbos and immerses on Motza'ei Shabbos. And, the Halachah is that she does Chafifah only at night, i.e. on Motza'ei Shabbos, and she does not rush to do Chafifah on Erev Shabbos.

Explanation #3 (cont.): [This is when it is possible] to do Chafifah on Motza'ei Shabbos, for it is not Yom Tov, she does Chafifah then, and does not rush to do it on Erev Shabbos;

And this [other law] is when it is not possible to do Chafifah on Motza'ei Shabbos, which is Leil Tevilah, e.g. it is Yom Tov. She does Chafifah on Erev Shabbos, even though her Tevilah is on Motza'ei Shabbos or Sunday night, and there are two days of Yom Tov after Shabbos;

The Gemara does not discuss at all the Isur of Chafifah in the morning and Tevilah at night without a [full] day in between.

Similarly, it does not discuss the Isur of Chafifah at night.

Pesak (Ri): If Leil Tevilah falls on Tish'ah b'Av, it is forbidden to immerse, for the Halachah does not follow the Beraisa in Shabbos (111a) that anyone obligated to immerse, he immerses normally, whether on Tish'ah b'Av or Yom Kipur;

Rather, we hold like R. Chanina Segan ha'Kohanim, who says in Ta'anis (13a) that the Beis ha'Mikdash is worthy that we lose one Tevilah [due to mourning its loss] in a year;

Support #1: It says about this in the Yerushalmi in Beitzah that R. Levi ruled like R. Chanina Segan ha'Kohanim's teaching.

Support #2: Also, we can say that the Gemara in Shabbos [permitted immersing on Tish'ah b'Av) in the days of the Tana'im, when they needed to engaged in Taharos on Tish'ah b'Av. Therefore, she was permitted to immerse at night;

Nowadays that she immerses only for her husband [and Bi'ah is forbidden on Tish'ah b'Av], she can do Chafifah and immerse on Motza'ei Tish'ah b'Av;

If she will not have time to bathe and do Chafifah at night, she bathes and does Chafifah Erev Tish'ah b'Av, so it will be easy for her to do a little Chafifah on Motza'ei Tish'ah b'Av and immerse.

Question: We should challenge R. Yosi! Here he says that it suffices to separate in the morning;

Above (53a), R. Yosi said "if a Nidah did not separate in Taharah from [the time of] Minchah and onwards, does she not have Chezkas Tum'ah?!" This shows that she must separate from Minchah and onwards! (Meforshim argue about whether this is Minchah Ketanah (two and a half hours before night), Plag ha'Minchah (one and a quarter hours before night), or shortly before Bein ha'Shemashos).

Answer: There, we discuss when she separated on the day that she saw [blood] in the morning. Here we discuss when she checked in the morning and found that she is Tehorah.

Question: If so, when we challenge R. Yehudah "if her hand was in her eyes (she was checking) all of Bein ha'Shemashos...", R. Yosi should challenge himself, for also he requires separating after Minchah when she separated on the day that she saw!

How does it help to delay [separating until the time of Minchah]? Perhaps she saw right after removing her hand!

Answer: It is not difficult for him. Since she was established to see the morning, it is proper to obligate her to separate from Minchah and onwards, without a stringency, rather, based on letter of the law;

We should not be stringent and say that perhaps she saw right after removing her hand, to obligate Bedikah at the end of the day;

However, R. Yehudah comes to be stringent and consider it a Safek. Even when she did not see in the morning, rather, she checked and found herself Tehorah, he obligates separating also at the end of the day. He should be stringent to obligate her to check, lest she saw right after removing her hand!

Implied question: We do not rule based on [what it says in a Mishnah or Beraisa, about whom the Halachah follows]!

Answer: We rule above (7b) like R. Eliezer in four [places in Taharos] and this is one of them.