Question: A Mishnah in Parah (12:11) says that we may not immerse the Ezov at night and sprinkle during the day, but the person himself may immerse at night and we sprinkle on him during the day;

Here we say that he must immerse during the day!

Answer (R. Tam): There are two Tevilos. One is before Haza'ah, in order to receive the Haza'ah. It may be at night, like it says in Yevamos (46b);

One is after Haza'ah. This is the one written in the verse. It is during the day.

Support: Kerisus 9a connotes that there is Tevilah before Haza'ah;

Citation (9a): Just like your ancestors entered the Bris only through Milah, Tevilah and acceptance of blood...

We learn from acceptance of blood from "va'Yizrok Es ha'Dam". We learn Tevilah from a tradition that there is no Haza'ah without Tevilah beforehand in order to receive the Haza'ah;

Haza'ah of Parah Adumah is in place of [that] Haza'ah. If so, it requires Tevilah beforehand.

Source: We require also Tevilah afterwards, for it was taught in the Sifri that if one did Tevilah before Haza'ah, it did not do anything.

Conclusion: We require Tevilah afterwards, like it connotes there, and one before, like it connotes in Kerisus and several places in our Gemara, which mention Tevilah before Haza'ah.

Question: In any case, it is difficult. Which Tevilah do we discuss here?

If it is the Tevilah before Haza'ah, like the words connote, for it mentions Tevilah first, it can be even at night, like I explained;

If it is the Tevilah after Haza'ah, why does it say [that it must be during the day] because it is equated to Haza'ah? We know this because it is after Haza'ah, so it is during the day!

Suggestion: Perhaps the Hekesh teaches that it may not be on the following night, i.e. the eighth night.

Rejection: We do not need a Hekesh to teach about this. Since the seventh passed, obviously he may immerse whenever he wants!

Support: Also Rashi explained that after the day passed, he may immerse at night.

Answer: Rather, Riva's Perush is correct. Here we discuss Tevilah of the Ezov, which is during the day, like the Mishnah in Parah. This is why it says "we immerse, and afterwards sprinkle."

Support: The Yerushalmi expounds "v'Taval... v'Hizah", to equate Tevilah to Haza'ah, i.e. Tevilas Ezov.

Question (Ri): We say in Yoma (88a) that a Zav, Zavah and Tamei Mes immerse during the day. R. Yosi says, he may not immerse from Minchah and onwards;

Explanation: He may not immerse after Tefilas Minchah, because he can pray Ne'ilah at night.

Obviously this is during the day after Haza'ah. If it were before Haza'ah, why may one immerse on Yom Kipur?!

Suggestion: It is permitted on Yom Kipur because Tevilah bi'Zmanah Mitzvah (it is a Mitzvah to immerse to become Tahor on the first day possible).

Rejection: Haza'ah is forbidden due to Shevus (mid'Rabanan), like it says in Pesachim (65b). How may he do it?

Suggestion: Haza'ah was yesterday (Erev Yom Kipur), and now he immerses on the eighth day.

Rejection: This is not Tevilah bi'Zmanah. It does not override Yom Kipur!

Answer: We must say that he received Haza'ah from a minor, or he was Shogeg, or transgressed and sprinkled.

Question: In Shabbos (132a) we expound this verse to teach even on Shabbos. [R. Yochanan] expounds "Ben Shemonas Yamim" to exclude [Bris Milah] at night. A Beraisa supports R. Yochanan!

Answer: Here we bring the simpler Drashah, like [we do regarding] seeing Tzara'as.

Note: In Sanhedrin 34b, we learn from "uv'Yom Hera'os Bo" that we check Tzara'as during the day, and in Mo'ed Katan (8a) we learn this from "k'Nega Nir'eh Li" (and not to my lamp), and expound uv'Yom Hera'os differently.

Question (R. Efrayim): Since Milah is not at night, it is a Mitzvas Aseh sheha'Zeman Gerama], from which women are exempt;

If so, in Kidushin (29a), why do we need "Oso" to teach that a woman is exempt from circumcising her son? We already know this, for it is a Mitzvas Aseh sheha'Zeman Gerama!

Answer #1: One might have thought that they are exempt from Mitzvas Aseh sheha'Zeman Gerama only when there is no Kares...

[I.e. Mitzvos] like Matzah, Simchah and Hakhel, which have no Kares. From them, we exclude women from (Mitzvas Aseh sheha'Zeman Gerama. In Kidushin 35a, we say that these are Sheloshah Kesuvim that obligate women in such Mitzvos. We infer that they are exempt from all others.)

However, Milah, which has Kares, and 13 covenants were made over it, one might have thought that women are obligated to circumcise their sons. "Oso" teaches that this is not so.

Answer #2: [We need "Oso" to teach about] Milah not in its time (after day eight), according to the opinion that it may be done during the day or at night.

Observation: If above, "we do not immerse" applies to a person immersing, we understand why the Gemara asks why Shomeres Yom k'Neged Yom was singled out;

Implied question: However, if it refers to immersing the Ezov, what is the question?

Answer: We must say that we ask why we taught that Shomeres Yom k'Neged Yom immerses during the day, more than anyone else who must immerse.

Rashi's opinion (Pesachim 81a): We ask according to R. Yosi, who say that Miktzas ha'Yom k'Kulo (part of the day counts like the whole day), and if a Zavah [who must count seven clean days before she can become Tehorah] saw on her seventh day, it does not nullify her count. (Since the beginning of the day was clean, it is as if she completes seven clean days.)

Citation (81a) - Question: According to R. Yosi, how can a woman become a Zavah Gedolah? (If the beginning of the second or third day was clean, it is as if a clean day interrupted!)

Citation (cont.) Answer: The case is, on two consecutive days she saw all of Bein ha'Shemashos, so the end of each day and the beginning of the next day was b'Tum'ah.

Note: Rashi there said that we needed to say that she saw all of Bein ha'Shemashos. It was not enough to say that she saw at night, for counting at night is counting.

Question (against Rashi): Why didn't we say that she saw at night? Counting at night is not counting, so the entire day was Tamei, since it began Tamei!

Answer: R. Yosi holds that the end of the day counts for Shimor (counting clean days), just like the beginning of the day.

Support - Citation (Nazir 16a) Question: According to R. Yosi, how can a woman become a Zavah Gedolah? If she saw in the middle of the day, the rest of the day is Shimur!

Question: If so, R. Yosi holds that Miktzas ha'Yom k'Kulo, we should have asked that he holds like the Kusim, like we asked against Rav in Nidah (69a)!

Answer: The Kusim hold that even from the first day that she stopped seeing, she counts it like the first [of the seven clean days]. R. Yosi says [that Miktzas ha'Yom k'Kulo] only for the seventh day.

Question: Since we hold that at Tzeis ha'Kochavim it is night, why do R. Yosi and R. Yehudah argue about Bein ha'Shemashos (which is Safek day, Safek night)? They should say at Tzeis ha'Kochavim [it is night]!

Answer: There is a distinction even regarding the Shi'ur of Tzeis ha'Kochavim. There are big stars that are seen during the day. (We must see medium stars.)

Question - Citation (Berachos 2b): Tzeis ha'Kochavim is night. Even though there is not a proof, there is an allusion to this - "v'Hayah Lanu ha'Laylah l'Mishmar."

Why isn't it a full proof, like we derive here from the verse?

Answer: There, we wanted to conclude that the time of lying down regarding Keri'as Shema is Tzeis ha'Kochavim;

Therefore, it is not a full proof, for even though it is night then, not everyone is lying down then.

Question: Why do we need this? The Tana taught that the entire day is Kosher for Semichah. Viduy is only at the time of Semichah!

Answer: If not for this, one might have thought that this Viduy is unlike the Viduy of other Semichos, and it is not Kosher the entire day, and this would cause that also Semichah is not Kosher the entire day, [un]like other Semichos;

Therefore, it needed to teach Viduy.

Explanation: We do not learn Shechitah from this verse, for it is not an Avodah, for it is Kosher through a Zar. The verse discusses Avodah, for it says "Lehakriv Es Korbaneihem";

Similarly, in a Minchah, Tenufah and Hagashah do not require a Kohen, [for they are] before Kemitzah. (Mitzpas Eisan - in Kidushin (36a,b) and Menachos (9a), Tosfos says that these require Kehunah! It seems that Tosfos holds that this is l'Chatchilah, but b'Di'eved they are Kosher through a Zar, like the Rambam says, therefore the verse does not discuss them.)

R. Tam's opinion: If one forgot to [count the Omer and] bless at night, he does not bless during the day. Our Stam Mishnah connotes like this;

Implied question: A Stam Mishnah in Menachos (71a) says that if the Omer was reaped during the day, it is Kosher b'Di'eved! (In Menachos 72a, we say that Tana'im argue about whether nighttime Mitzvos are Kosher during the day. According to that Mishnah, one may count and bless during the day!)

Answer #1: In any case, the Stam Mishnah here is preferable, for it was taught regarding clearcut Halachos;

Answer #2: It seems that even according to the opinion that is Machshir Ketziras ha'Omer during the day b'Di'eved, he agrees that one may not bless on Sefiras ha'Omer during the day;

This is because the Torah taught twice [that one must count at night] to make it Me'akev. It says "Temimos" - the weeks are full only if you count at night.

Note: The Rashash asked why we need a second verse to show that it is Me'akev. We need this only for Kodshim. It is hard to say that Sefiras ha'Omer is Kodshim!

Support: It says so also in Halachos of Shavu'os.

Bahag's opinion: If one forgot to [count the Omer and] bless at night, he counts the next day without a Berachah. This is the Halachah.

Note: Seemingly, this is just like R. Tam! Others cite Bahag to say that he counts with a Berachah (Ran, and Tosfos Menachos 66a connotes like this - Rashash). Alternatively, Tosfos cites Bahag for the Chidush just below this, which Tosfos (66a) utterly rejected.

Distinction: However, if one forgot one night, he does not count afterwards with a Berachah. We require "Temimos" (full weeks), and this is not fulfilled.

Observation: After blessing on Sefiras ha'Omer, one says "may it be Your will to rebuild [the Mikdash...]". We do not say so after [blessing on] the Shofar or Lulav.

Explanation: This is because it (Sefiras ha'Omer) is only a commemoration now of [the Mitzvah we will have at the time of] Binyan Beis ha'Mikdash. However, Shofar and Lulav have an Aseh.

Note: Rashash questions the Hava Amina to pray for Binyan Beis ha'Mikdash after Teki'as Shofar, which is mid'Oraisa even nowadays. It seems that Tosfos does not discuss Teki'as Shofar of Yom Kipur, which commemorates Yovel (PF).