Explanation #1 (Rashi): This is because it says "Ki Yasir" (if a Nochri marries your daughter, he will veer your son, i.e. grandson, away from Me), and it does not say Ki Sasir";

Inference: The verse does not discuss "do not take his (a Nochri's) daughter for your son", for if she bears a child for idolatry, he is not called your son, and we do not apply "she will veer your son (grandson) away from Me";

Rather, it refers to "do not give your daughter to his son." The verse means that perhaps she will gave birth to a son, and the father will veer him away from Me, for he (her son) is called your son (he is a Yisrael).

Question #1 (R. Tam): Rashi explains that "your [grand]son is called your son" refers to your [grand]son from a Yisraelis. His (the grandson's) father is a Nochri. "Ki Yasir" refers to him (the father).

If so, why do we bring Ravina's teaching "the son of your daughter..."? This is exactly what Shmuel taught!

Question #2: (On 23a, R. Yochanan) learns from "Ki Yasir" that your son from a Yisraelis is called your son, but your son from a Nochris is called her son.) Why does Ravina say "we learn from R. Yochanan" [that the son of your daughter from a Nochri is called your son]? "We learn from" is not appropriate, for this is exactly the words of R. Yochanan!

Explanation #2 (R. Tam): "Ki Yasir" refers to "do not take his (a Nochri's) daughter for your son." The Chosen (her father) will veer your son away from Me.

This veering means that the children are not attributed to your son, rather, to the Nochris. It is not called your son, rather, her son.

Shmuel and R. Yochanan did not explain anything about a Nochri who has Bi'ah with a Yisraelis;

Rather, Ravina infers that the son of your daughter from a Nochri is called your son, since it does not say "he will veer your daughter";

Inference: There is no veering here, for the lineage [of her children] follows her.

Question #1 (Ri): "Ki Yasir" connotes straying from [service of] Hash-m, like the Targum "that he will cause him to err."

Question #2: We also expound "Ki Yasir" to include all who cause to stray (i.e. all Nochrim).

Explanation #3 (R. Tam): Shmuel and R. Yochanan infer from "Ki Yasir Es Bincha" that the Torah is concerned only for his (your son's) veering, lest he (his Nochri father-in-law) make him err;

The Torah is not concerned for your son's son veering, for since he comes from a Nochris, he is not called your son, rather, her son, since it does not say 'he will veer them' or ''he will veer your son and his seed away from Me.'

Ravina infers "we learn from this that the son of your daughter from a Nochri is called your son, for only regarding your son (marrying a Nochris), "Ki Yasir Es Bincha" excludes his seed, but regarding your daughter, even in his (the Nochri's) seed there is concern for veering.

Implied question: In Kidushin (49b) we say that 10 measures of brazenness descended to the world. Meishan received nine, and the rest of the world received one. This is because they (Bnei Meishan) are Mamzerim;

Why didn't it mention Tarmod? They are more Pasul!

Answer #1: Perhaps Pesulim went from Tarmod to Meishan until Meishan because worse than Tarmod.

Answer #2: Perhaps Tarmod was mostly Nochrim, and Meishan was mostly Yisrael.

Explanation: Bavel is called "She'ol", because initially everyone was exiled to Bavel, both Kesherim and Pesulim, and from Bavel all of the Pesulim went to Tarmod, like it says in Kidushin (69b), that Ezra did not leave Bavel until he [removed all of the Pesulim and] made it like clean fine flour.

It lists the order in which the Pesulim went from one place to another, just like the Kav rolls from here to there. (Maharsha - Kav is a measure. This alludes to Kidushin 49b, which says that 10 Kavim of brazenness (a Siman of Mamzerus - Kalah 2:1) came to the world; Meishan received nine of them.)

Explanation: There is no need for the Seifa (18b), for we learn it from the Reisha;

Rather, since it was taught in the Reisha, also the Seifa taught it [for parallel structure].

Implied question: Here, why didn't we ask why the one who teaches "Rishonah" did not teach "Sheniyah"?

In Avodah Zarah (2a), we ask the one who teaches "Eidiehen" (with an Aleph) did not teach "Eidiehen" (with an Ayin)!

Answer: There, we ask because it should have taught an expression of "Edus" (with an Ayin, i.e. testimony), like it says "Yitnu Edeihem v'Yitzdaku";

After we answer that it is better to teach an expression of destruction, we ask why the one who teaches "Eidiehen" (with an Ayin) did not teach "Eidiehen" (with an Aleph).

Question: We should know this from "Deracheha Darchei No'am!"

This is the reason why we consider the dead as if they were alive regarding Yibum (below 87b. If a man died with children, the widow does not become Zekukah l'Yibum after his children die.)

Implied question: (Why is Tosfos' question difficult?) We need [Yachdav] for other matters, like we say below (24a) "if so, why did the Torah write Eshes Achiv she'Lo Hayah b'Olamo"!

Also, we derive from it (111b) that a minor is Zokek l'Yibum!

Answer: The Gemara connotes that we need the verse for the law itself.

Answer (Ri): We need it for when the Yevamah's mother-in-law is pregnant. It is [not a contradiction to] Darchei No'am if she would need to wait to see if she gives birth to a boy, and she will be Zekukah to him.

Implied question: Regarding Eshes Achiv she'Lo Hayah b'Olamo, why can't we learn from Bnei Yakov that they are called brothers only if they were alive at the same time?

Answer: It is obvious that they are called brothers [even if they were not alive at the same time]. Had the Torah not explicitly excluded [Eshes Achiv she'Lo Hayah b'Olamo], we could not have learned this from Bnei Yakov.

Explanation #1 (Rashi): [This refers to] Rabanan of R. Yehudah ben Beseirah, whom we bring below.

Since Shmuel rules like R. Yehudah ben Beseirah, who says that Yesh Zikah, this implies that Rabanan disagree.

Question: Perhaps normally, Rabanan hold that Yesh Zikah, but there they permit, and do not require her to wait for the brother to do an act, because Kidushin uproots Zikah!

Below (83a) and in Megilah (18b), we consider R. Yehudah ben Beseirah to be a lone opinion, for we derive from it that Shmuel is concerned for an individual, since he rules like R. Yehudah ben Beseirah!

Why is it considered a lone opinion? Several Tana'im hold that Yesh Zikah, and Rav Ashi infers that the Stam Mishnah (30a) holds that Yesh Zikah even with two brothers!

Conclusion: Rather, surely all [others] agree [that Ein Zikah] in the case of R. Yehudah [ben Beseirah], for through the Kidushin, the Zikah is uprooted.

Implied question: Below (18b), we show why Shmuel needed to teach two laws (Yesh Zikah, and the Halachah follows R. Yehudah. We did not say that "Yesh Zikah" would not suffice, lest we think that he rules unlike R. Yehudah!)

Answer: We could have said that had he only taught that Yesh Zikah, one might have thought that in R. Yehudah's case, Kidushin uproots Zikah. Rather, we found another reason.

Explanation #2: One should not say that "like the one who holds that Ein Zikah" is R. Meir.

Rejection: Because, why did the Gemara say "one might have thought [that Ein Zikah] only when there are two brothers"? R. Meir says Ein Zikah even regarding one brother!

Explanation #3: We refer to R. Yehoshua, who says that a lone [Yavam] can annul [the vows of his Yevamah, but not when there are two [Yevamim].

Rejection: Below (29b), we establish the argument to be when he gave a Ma'amar. They argue about whether or not a Ma'amar acquires.

Answer (to Question (b), and support or Explanation #1): He holds that we do not distinguish due to Kidushin [according to the opinion that Yesh Zikah - R. Simchah d'Esvi];

Rav Yosef calls it an individual's opinion. He holds that all the Tana'im hold that Ein Zikah. He argues with Rav Ashi, who infers that the Mishnah (30a) holds that Yesh Zikah, for also there they argue with him.

Support: Below (50a), Rav Yosef says that we do not need the Mishnah that teaches that if a Yevamah died, the Yavam may marry her sister, even though in our Sugya we wanted to derive from it that Yesh Zikah;

Rav Yosef did not want to say that it teaches that Yesh Zikah, for he holds that all hold that Ein Zikah.

Suggestion: This is unlike R. Gamliel, who says "if she did Mi'un [by herself], she did Mi'un" (and her sister may do Yibum. However, we do not encourage her to do Mi'un.)

Rejection: He agrees here. There is different, for she (the Yevamah's sister) already married the brother.

Question: What is the source that he holds that Ein Zikah? Perhaps he holds that Yesh Zikah, and after death it is permitted because Zikah was uprooted, like we say below!

Answer: Even though the Gemara says why he needed to teach both, really, if there is Zikah, also after death is forbidden, for Zikah is not uprooted by itself (without an action).