(Mishnah - R. Meir): Even 40 or 50 days before birth, we attribute blood to the birth.

Question: It suffices to say that 50 days before we attribute. There is no need to say 40 days!

Answer (Rav Chisda): For a healthy woman we attribute 40 days, and for a sick woman 50 days.

Version #1 (Levi): We are Metaher blood (seen amidst Koshi) only if it comes in the days when she can become a Zavah. (Rashi - these are the 11 days after the seven days of Nidah. R. Chananel - it is the first nine of these days, for a first sighting on day 10 or 11 cannot lead to (full) Tum'as Zivah);

(Rav): We are Metaher blood even if it comes in the (following seven) days proper to count to become Tehorah.

(Rav Ada bar Ahavah): According to Rav, we are always Metaher (if the first sighting was in the days of Zivah), for all the following days are proper to count, if she would be Soser her count!

Question (against Levi - Mishnah - R. Meir): Even 40 or 50 days before birth, we attribute blood to the birth.

We understand according to Rav, as Rav Ada explained;

However, according to Levi, we are Metaher only 11 (or nine) days!

Answer: R. Meir did not say that she is Tehorah even if she saw on all these days. Rather, among the 40 or 50 days, if she saw during days of Nidah she is a Nidah. If she saw during days of Zivah she is Tehorah.

Version #2 (Levi): We are Metaher blood only if it comes in the days when she can (start to) become a full Zavah. (Tosfos citing Rashi - these are the first nine of the 11 days of Zivah. R. Chananel - they are the last nine of these days, when she can finish becoming a full Zavah.)

Question: What is his source?

Answer: It says "Damah Yamim Rabim" (her own blood, and not due to Koshi).

(Aba Sha'ul citing Rebbi): We are Metaher blood even if it comes in the days when she can become a Zavah Ketanah (through one or two sightings. I.e. we include all 11 days of Zivah);

Question: What is his source?

Answer: In the Parshah of Zavah we expound "Yemei" and "v'Kol (Yemei)" (to include Zavah Ketanah).

Question (against both of them - Mishnah - R. Meir): Even 40 or 50 days before birth, we attribute blood to the birth.

Answer: It does not say that she is Tehorah during all these days. Rather, if she saw during days of Nidah she is a Nidah. If she saw during days of Zivah, she is Tehorah.

(Beraisa - R. Meir): A woman can see blood amidst Koshi 150 consecutive days without becoming a Zavah:

The case is, she saw the last two days of (the 11 days of) Zivah, then seven days of Nidah, then two days of Zivah, then 50 days of Koshi (and gave birth to a girl the next day), 80 days of Tum'as Yoledes and Dam Tohar for a Nekevah, seven days of Nidah, and two days of Zivah.

Rabanan: A woman can forever see blood every day amidst Koshi, without becoming a Zavah!

R. Meir: You allude to a woman who constantly miscarries females (within every 139 days -- 80 days of Yoledes, at most nine of Nidah and Zivah, and up to 50 days of Koshi before the next birth). You are wrong. The law of Koshi does not apply to miscarriages.

(Beraisa): A woman can see blood 100 consecutive days (without pain) and not become a Zavah:

The case is, she saw two days of Zivah, seven days of Nidah, two days of Zivah (and gave birth to a girl), 80 days of Yoledes, seven days of Nidah, and two days of Zivah.

Question: What is the Chidush?

Answer: (The Tana holds that) it is possible to give birth without blood (beforehand. If he held that she must see blood first, she would became a Zavah on the day of birth.)

(Mishnah - R. Yehudah): The law of Koshi applies only in her (last, i.e. ninth) month.

(Beraisa - R. Yehudah): The law of Koshi applies only in her (last) month. This is sometimes a stringency, and sometimes a leniency;

If she saw blood amidst Koshi for the last two days of the eighth month and the first day of the ninth month, even if she gave birth at the beginning of the ninth month, she is a Zavah. (The majority of the three days were in the eighth month, when the law of Koshi does not apply);

If she saw blood amidst Koshi on the last day of the eighth month and the first two days of the ninth month, she is not a Zavah. (The law of Koshi applies in the ninth month. It is as if she had only one day of Zivah.) This is even if she gives birth at the end of the ninth month.

(Rav Ada bar Ahavah): This shows that R. Yehudah holds that the Shofar (blown to herald the coming month) causes the law of Koshi. (It depends on the ninth lunar month declared by Beis Din from the beginning of pregnancy, not nine full (30 day) months. If Kishuy did not depend on Rosh Chodesh, she could not know which day begins the ninth month. Even if she knew from which Bi'ah she became pregnant, she does not know whether conception was that same day, or on one of the next two days!)

Question: (R. Yehudah holds that a woman can give birth at the beginning of the ninth month.) However, Shmuel taught that a woman gives birth after exactly 271, 272 or 273 days (nine full months after conception, which is on the first, second or third day) from Bi'ah!

Answer: Shmuel holds like the early Chasidim;

(Beraisa): The early Chasidim would have Bi'ah only on Wednesday (Tuesday night), to avoid the possibility of desecration of Shabbos (due to birth on Shabbos. Maharsha - also Bris Milah on Shabbos is called Chilul).

Question: According to Shmuel, if Bi'ah is on Wednesday, the baby will be born (on day 271, 272 or 273, i.e.) on Sunday, Monday or Tuesday. Even if Bi'ah was on one of the next three days, the baby would not be born on Shabbos!

Answer: The Beraisa means that they would have Bi'ah only on Tuesday night or later in the week.

(Mar Zutra): The early Chasidim learn from "va'Yiten Hash-m Lah Herayon." -- the Gematri'a of Herayon (pregnancy) is 271.

(Mar Zutra): Even according to the opinion that a nine month birth is always born after nine full months, a seven month birth can be born at the beginning of the seventh month -- "va'Yehi li'Sekufos ha'Yamim... va'Teled." Sekufos teaches two seasons (six months), and Yamim teaches another two days.

(Mishnah - R. Yosi and R. Shimon): The law of Koshi applies only in the two weeks before the birth.

(Shmuel): They learn from "v'Tam'ah Shevu'ayim k'Nidasah" -- there are two weeks in which she can become a Nidah, but not a Zavah, i.e. Koshi.

(Beraisa): A woman can see blood amidst Koshi for 25 consecutive days and not become a Zavah:

The case is, she saw the last two days of (the 11 days of) Zivah, then seven days of Nidah, then two days of Zivah, then 14 days of Koshi;

If she sees 26 days without giving birth, she must become a Zavah.

Objection: If she does not give birth, the law of Koshi does not apply. After three days (during Yemei Zivah) she becomes a Zavah!

Answer #1 (Rav Sheshes): It means, if she (sees 26 days and) gives birth.

Rejection (Rava): It says 'without giving birth'!

Answer #2 (Rava): Rather, it means that if she sees 26 days and gives birth, she must be Yoledes b'Zov;

If she miscarries, after only three days (during Yemei Zivah) she becomes a Zavah!

(The Tana holds that) the law of Koshi does not apply to miscarriages.

(Mishnah): If a woman saw blood amidst Koshi during (Yemei Tohar in) the 80 days after Yoledes Nekevah, all the blood is Tahor, until the birth;

R. Eliezer says, it is Teme'ah. (Rashi - this is whether it comes during the days of Nidah or Zivah. R. Menachem - it is only if it is during the days of Nidah.)

Chachamim: Normally, Dam Shofi (blood seen without pain) is more stringent than Dam Koshi (the former can cause Zivah). During Yemei Tohar, the Dam Shofi is Tahor, and all the more so Dam Koshi is Tahor!

R. Eliezer: Dayo (a Kal va'Chomer cannot teach more than what we learn from). Dam Koshi normally (i.e. not in Yemei Tohar) does not cause Zivah, but it causes Nidah, the same applies when it is seen during Dam Tohar.

(Gemara - Beraisa): "Teshev" includes a woman who saw Dam Koshi during Yemei Tohar of Yoledes Nekevah. All the blood is Tahor, until the birth;

R. Eliezer says, it is Tamei.

Chachamim: The Torah is more stringent about Dam Shofi before a birth than after a birth (i.e. during Yemei Tohar). The Torah is lenient about Dam Koshi before a birth. All the more so, it is lenient about Dam Koshi during Yemei Tohar!

R. Eliezer: Dayo! Dam Koshi before a birth does not cause Zivah, but it causes Nidah. The same applies when it is during Yemei Tohar!

Chachamim: We can learn the Kal va'Chomer the other way! Dam Shofi is more stringent than Dam Koshi. During Yemei Tohar, Dam Shofi is Tahor. All the more so Dam Koshi is Tahor!

R. Eliezer: Any way you learn, a Kal va'Chomer cannot teach more than either side we learn from. Dam Koshi does not cause Zivah, but it causes Nidah. The same applies when it is seen during Yemei Tohar.

(Rava): R. Eliezer can refute Chachamim (who are always Metaher)!

All expound "Damah" her (natural) Dam Zivah, to exclude blood due to birth, yet if it is seen during the days of Nidah she is a Nidah. We should say the same about "v'Taharah mi'Mekor Dameha"!

Version #1 - Rashi - Question (against R. Eliezer): Likewise, we should be Metaher Dam Tohar during Yemei Zivah, just like we learned from "Damah" before a birth!

Answer: "Teshev" -- all Dam Tohar has the same law. (During the days of Nidah it is Tamei, and also during Yemei Zivah.)

Version #2 (R. Menachem) culmination of question against Chachamim: Chachamim should be Metaher only during Yemei Zivah, but if she sees during the days of Nidah, she should be a Nidah!

Answer: "Teshev" teaches that all Dam Tohar has the same law. (During Yemei Zivah it is Tahor, and also during the days of Nidah.)