Rav Hillel: In any case, I saw that they were listed as forbidden!

Rav Ashi: If you saw that they were permitted, you would not rely on it, since Mar brei d'Ravna didn't sign on it!

For the same reason, don't rely on what you saw that they are forbidden.

(Beraisa - d'Vei R. Chiya): The third (generation granddaughters) from his son and daughter and from his wife's son and daughter are Sheniyos;

The fourth (generation of grandmothers from his father-in-law and mother-in-law are Sheniyos.

Question (Ravina): (The wife's great grandmother and great granddaughter are Sheniyos.) Why does his wife count towards the generations above her (so the fourth is called a Sheniyah), but not towards the generations below (the third is called a Sheniyah)?

Answer (Rav Ashi): The generations above are forbidden due to her, but the generations below are not (they are forbidden due to him).

Objection: The (great grand)son and (great grand)daughter of his wife are forbidden because of her, yet she is not counted among the generations!

Answer: Since we counted three generations below himself and did not count himself, we also do not count her among the generations below her.

Question (Rav Ashi): Do the Sheniyos of R. Chiya extend to all generations?

Answer #1 (Rav Kahana): Since Rav (21a) listed only four that do not extend, this shows that all others extend.

Rejection: Perhaps Rav referred only to Sheniyos in that Beraisa!

Answer #2: R. Chiya said that the third/fourth generations below/above are forbidden. This shows that past that are permitted!

Rejection: Perhaps he forbids from the third/fourth and onward.

Question (Rava): In Eretz Yisrael, they asked whether or not Sheniyos apply to converts.

Answer (Rav Nachman): Even Arayos are forbidden to converts only so they will not say that they descended to a lower Kedushah (e.g. 'before converting I was forbidden to my mother. Now I am permitted!'). Certainly, there was no decree of Sheniyos!

(Rav Nachman): Maternal brothers who converted should not testify for each other. If they did, the testimony stands. (Converted) paternal brothers may testify for each other.

(Ameimar): Even maternal brothers may testify for each other.

Question: Why is this different than Arayos?

Answer: Arayos pertain to every person (if we permit Arayos to converts, perhaps Yisraelim will marry Arayos). Testimony is received by Beis Din. (Beis Din will not err; they know that) a convert is like a newborn.

(Mishnah): A brother from any place (i.e. mother) obligates his brother's wife to do Yibum or Chalitzah. He is like a brother in every respect;

The only exceptions are a brother from a slave or Nochris.

A son from any place (i.e. mother) exempts his father's wife from Yibum and Chalitzah. He is liable for striking or cursing his father. He is like a son in every respect;

The only exceptions are a son from a slave or Nochris.

(Gemara) Question: What does 'from any place' come to include?

Answer (Rav Yehudah): It includes a Mamzer.

Objection: Obviously, he is his brother!

Answer: One might have thought that a Gezeirah Shavah "Achvah-Achvah" from Yakov's sons teaches that just like there they are proper, also Yibum depends on proper brothers;

The Mishnah teaches that this is not so.

Question: What is the reason?

Answer: Since a Mamzer exempts (his mother) from Yibum, he also is Zokek (obligates his brother's widow to do Yibum or Chalitzah).

(Mishnah): He is his brother in every respect.

Question: What does this teach?

Answer: When the Mamzer dies, his brother inherits him, and (if he is a Kohen) becomes Tamei to bury him.

Objection: This is obvious, for he is his brother!

Answer: A Kohen becomes Tamei "Ki Im li'Sh'eiro ha'Karov Elav" (only for his close relatives);

We learned that "She'eiro" refers to his wife;

"Lo Yitama Ba'al b'Amav Lehechalo" teaches that a husband does not become Tamei in every case. He becomes Tamei for a permitted wife, but not for a forbidden wife.

One might have thought that here also, he makes himself Tamei for a proper brother, but not for an illegitimate brother. The Mishnah teaches that this is not so.

Question: What is the reason?

Answer: The forbidden wife is destined to be divorced. This does not apply to a brother who is a Mamzer.

(Mishnah): Except for a child from a slave or a Nochri.

We learn from "The woman (Shifchah) and her children will be to her master" (i.e. the children are slaves, like her. Below (23a) we discuss children of a Nochris.)

(Mishnah): Any child exempts from Yibum and obligates his brother's wife to do Yibum (or Chalitzah).

Question: What does 'any' come to include?

Answer (Rav Yehudah): It includes a Mamzer;

We read "U'Ven Ein Lo" like 'Ayen' (investigate to see if he has any son, even a Mamzer).

(Mishnah): He is liable for striking (or cursing) his father.

Question: The Isur "Do not curse a Nasi in your nation" applies to one who acts like your nation. (Likewise, there is no Isur to curse a wicked father, e.g. one who fathered a Mamzer!)

Answer: We answer like Rav Pinchas said (elsewhere). The case is, he repented.

Question: Can he really repent for this?

(Mishnah - R. Shimon ben Menasya): "The crooked cannot be fixed" applies to one who had Bi'ah with Ervah and fathered a Mamzer!

Answer: In any case, now he acts like your nation.

(Beraisa): One who has Bi'ah with his sister, who is the daughter of his father's wife, is liable for both of these Arayos;

R. Yosi bar Yehudah says, he is liable only for Achoso.

Question: What is the Chachamim's reason?

Answer - Question: Since it says "Ervas Achoscha Vas Avicha O Vas Imecha", why must it also say "Ervas Bas Eshes Avicha Moledes Avicha Achoscha Hi"?

Answer: This is Mechayev (one who has Bi'ah with a sister born through wedlock) for both of these;

R. Yosi b'Rebbi Yehudah expounds "Achoscha Hi" - you are liable only for this.

Chachamim use "Achoscha Hi" to teach that one is liable for a full sister.

This teaches that we do not punish from a Kal va'Chomer. (Even though one is liable for a half-sister, another verse is needed to be Mechayev for a full sister.)

R. Yosi b'Rebbi Yehudah says, "Achoscha" would suffice to teach this. "Hi" is extra, to teach that he is liable only for this.

Chachamim say, if not for "Hi", one would think that normally we punish from a Kal va'Chomer;

Question: If so, why would the Torah have written "Achoscha"?

Answer: The Torah sometimes writes things that could be learned from a Kal va'Chomer.

R. Yosi b'Rebbi Yehudah says, if so "Achoscha Hi" should have been written in the other verse.

Question: What does R. Yosi b'Rebbi Yehudah learn from "Bas Eshes Avicha"?

Answer: This teaches that the mother could be married to your father. It excludes a sister from a slave or Nochris, for the mother could not be married to your father.

Suggestion: Perhaps it excludes a sister from a woman raped by his father!

Rejection - Contradiction (Rava): "Ervas Bas Bincha O Vas Bitcha Lo Segaleh" implies that your wife's granddaughters (who are not from you) are permitted. However, "Ervas Ishah u'Vitah Lo Segaleh Es Bas Benah v'Es Bas Bitah..." forbids them!

Resolution (Rava): If a man raped or enticed a woman, he is permitted to her granddaughters that are not from him. If he married a woman, all her granddaughters are forbidden.