(Mishnah) Question: What (Isur between the parents) causes the child to be a Mamzer?

Answer #1 (R. Akiva): It is when they are She'er (relatives) forbidden to each other by a Lav;

Answer #2 (Shimon ha'Temani): It is when there is Kares (for Bi'ah).

The Halachah follows him.

Answer #3 (R. Yehoshua): It is when there is Misas Beis Din.

Support (Ben Azai): I found a scroll of lineage in Yerushalayim that said 'Ploni is a Mamzer from a married woman'.

If a man's wife dies, he may marry her sister. If he divorced her and then she died, he may marry her sister. If she married someone else and died, he may marry her sister.

If a Yevamah died, the Yavam may marry her sister. If he did Chalitzah and she died, he may marry her sister. If she married another man and died, he may marry her sister.

(Gemara) Question: What is R. Akiva's source?

Answer: "Lo Yikach Ish Es Eshes Aviv v'Lo Yegaleh Es Kenaf Aviv" - a man will not have Bi'ah with a woman with whom his father had Bi'ah;

R. Akiva holds like R. Yehudah, who says that this refers to a woman raped by his father, which is a Lav (for the son).

This is written next to the Isur of a Mamzer, to teach that such unions produce Mamzerim.

R. Simai says that even Chayavei Lavin not of She'er (produce Mamzerim), and R. Yesheivav includes even Chayavei Aseh. They include these from [the Vov in] "v'Lo".

R. Shimon ha'Temani holds like Chachamim, that "Kenaf Aviv" refers to a Shomeres Yavam of his father, which is Chayavei Kerisus (since she was his uncle's wife);

The Isur of a Mamzer is next to this. This shows that Chayavei Kerisos produce Mamzerim.

R. Yehoshua disagrees, for if so the verse should have mentioned only "Kenaf Aviv". Why does the Reisha of the verse discuss Eshes Av?

Rather, this teaches that Mamzerim result only from Arayos as stringent as Eshes Av (Chayavei Misos) until (but not including) Kenaf Aviv (Chayavei Kerisus).

(Abaye): All agree that a Mamzer does not result from Bi'ah with a Nidah or a Sotah.

Children of a Nidah are not Mamzerim because the Isur does not inhibit Kidushin;

"U'Sehi Nidasah Alav" - even when she is Nidah, Havayah (Kidushin; Havayah and 'u'Sehi' have the same root) takes effect on her.

Also the Isur Sotah does not inhibit Kidushin.

Support (Beraisa): All agree that the child of a Nidah, Sotah, or a Shomeres Yavam (who conceived from a stranger) is not a Mamzer.

Abaye did not teach the case of Shomeres Yavam, for he was unsure if the Halachah follows Rav (who says that Ein Kidushin Tofsin to a stranger) or Shmuel (who says that perhaps the verse comes (only) to forbid Bi'ah with a stranger).

(Beraisa - Shimon Ben Azai): I found a scroll of lineage in Yerushalayim that said that Ploni is a Mamzer from a married woman;

The scroll also said that the teachings of R. Eliezer ben Yakov are few but clean (the Halachah always follows him);

It also said that Menasheh killed Yeshayahu.

(Rava): He judged him and killed him.

Menasheh: Your Rebbi Moshe said (in the Torah) "A person will not see Me and live", but you said "I saw Hash-m sitting on a lofty throne"!

Your Rebbi Moshe said "Who is like Hash-m Elokeinu whenever we call to Him", but you said "Seek Hash-m when He is found"!

Your Rebbi Moshe said "I will complete the number of your days", but you said (to my father Chizkiyahu) "I will add 15 years to your days"!

Yeshayahu (reasoning to himself): Menasheh will not accept my answers. If I answer, I will make him an intentional sinner!

Yeshayahu said a name of Hash-m, and was swallowed into a cedar tree. They brought the tree and were sawing it. When they got to the place of his mouth, he died, because he had said (earlier) "I dwell among a people of unclean lips".

Question: How can we resolve Menasheh's questions?

Answer (for "I saw Hash-m" - Beraisa): All (other) Nevi'im saw Hash-m through a glass that distorts; Moshe saw through a clear glass (Rashi - only Moshe realized that he did not really see Hash-m).

Answer (for "Seek Hash-m when He is found"): Hash-m is always found to a congregation, but not always to an individual.

Question: When is He found to an individual?

Answer (Rav Nachman): He is found during the 10 days between Rosh Hashanah and Yom Kipur.