1) THE PROHIBITION AGAINST MARRYING A "NESINAH"
OPINIONS: The Mishnah discusses the penalty a man must pay to the father of the girl he raped (Devarim 22:28-9). The Mishnah lists girls ("Na'aros") for whom a man is fined even though they are prohibited for him to marry. Included in the list is a "Nesinah."
Who is a "Nesinah" and why is she prohibited?
(a) RASHI (DH Nesinah) explains that a Nesinah is a girl from the nation of Giv'on, the members of which are forbidden to marry into the Jewish people due to a prohibition enacted by David ha'Melech. They are called "Nesinim" (literally, "those who are given over") based on the verse, "Yehoshua gave them over (va'Yitnem) as hewers of wood" (Yehoshua 9:27). In the times of Yehoshua, the Giv'onim (members of the Chivi nation, one of the seven nations whom the Jewish people were commanded to destroy upon their entry into Eretz Yisrael) presented themselves to Yehoshua as though they had come from a far-away land. Under the pretense that they were not native residents of Eretz Yisrael, they requested to make peace with, and to join, the Jewish people. After Yehoshua agreed to accept them, it was discovered that they indeed were one of the seven nations prohibited from joining the Jewish people. Since he had already agreed to accept them, Yehoshua did not want to violate his word (even though they tricked him and his oath was uttered in error) so as not to cause a Chilul Hash-m. Yehoshua accepted them as converts but appointed them as woodchoppers and water-drawers to supply the provisions for the sacrificial service on the Mizbe'ach (Yehoshua 9:3-27).
Rashi clearly maintains that the Isur of Nesinah is an Isur d'Rabanan. Rashi's opinion is based on the Gemara in Yevamos (78b-79a) which states that Moshe Rabeinu decreed a prohibition against marrying the Nesinim of his generation, and Yehoshua extended the decree to last as long as the Mishkan or Beis ha'Mikdash would stand. David ha'Melech later extended the decree to include all subsequent generations, even when the Beis ha'Mikdash would not be standing.
(b) TOSFOS challenges Rashi's opinion that the Nesinim are prohibited only mid'Rabanan. The Gemara later (29b) cites a Beraisa which explains the verse in Devarim (22:29), "And she will be (Tiheyeh) to him for a wife," which refers to the rapist's obligation to marry his victim. Shimon ha'Timni derives from the word "Tiheyeh" that the rapist is obligated to pay the fine only to a victim with whom "Havayah" -- marriage -- would take effect b'Di'eved. Rebbi Shimon ben Menasya limits the obligation further and derives from the word "Tiheyeh" that one is obligated to pay the fine only to a woman whom he is allowed to marry l'Chatchilah. Rebbi Zeira explains that the difference between the two teachings is a case of a man who rapes a Mamzeres or a Nesinah. According to Shimon ha'Timni, he must pay the fine in such a case because Kidushin with a Mamzeres or Nesinah is binding b'Di'eved, even though he is prohibited from marrying her l'Chatchilah. According to Rebbi Shimon ben Menasya, he pays no fine in such a case because he is prohibited from marrying her l'Chatchilah. The fact that the Gemara discusses the prohibition against marrying a Nesinah in the context of its discussion about a verse in the Torah clearly indicates that the prohibition against marrying a Nesinah is an Isur d'Oraisa. Tosfos cites other sources which clearly indicate that the prohibition is an Isur d'Oraisa.
(According to Tosfos, the "decrees" (Yevamos 79a) against the Nesinim were not prohibitions against marriage, as Tosfos maintains that marriage with the Nesinim is prohibited mid'Oraisa. Rather, they were decrees of servitude.)
How does Rashi understand the sources which imply that the prohibition against marrying Nesinim is an Isur d'Oraisa?
1. Tosfos suggests, in an attempt to explain the view of Rashi, that the Gemaras which he cites as proof against Rashi's opinion may be referring only to a Mamzeres, not to a Nesinah. Perhaps only the Isur of Mamzeres is mid'Oraisa, while the Isur of Nesinah is mid'Rabanan.
Tosfos questions this approach. Even if it was David ha'Melech who enacted the prohibition against marrying a Nesinah, she still should be prohibited mid'Oraisa. David ha'Melech's enactment gave them the status of slaves (through the mechanism of "Hefker Beis Din Hefker"), and the Torah prohibits a Jew from marrying a slave (Devarim 23:18). Tosfos concludes that Rashi maintains that David ha'Melech did not give them the full status of slaves, and thus they are not included in the Torah's prohibition against marrying slaves.
2. The PNEI YEHOSHUA asks that Rashi himself writes in Sanhedrin (51a, DH Kusi) that the verse, "Lo Sischaten Bam" -- "Do not marry them" (Devarim 7:3), applies to Nesinim. The Pnei Yehoshua explains that the verse forbids only marrying a Nesinah; it does not forbid promiscuous relations with her. Since that Mishnah refers to a man who rapes a Nesinah, Rashi does not mention the Isur d'Oraisa against marrying a Nesinah, but only the Isur d'Rabanan (enacted by David ha'Melech) against promiscuous relations with her. (The Pnei Yehoshua agrees with the suggestion of Tosfos that, according to Rashi, David ha'Melech did not decree that Nesinim should have the status of full-fledged slaves.)
3. In his second explanation of the words of Rashi, the Pnei Yehoshua points out that whenever Rashi discusses the Nesinim throughout Tanach and Shas he never mentions the verse which prohibits marriage with slaves (Devarim 23:18). The Pnei Yehoshua proposes that Rashi maintains that the verse of "Lo Sischaten" (Devarim 7:3) forbids one from marrying a Nesinah who herself was a member of the Giv'onim and converted; no verse forbids one from marrying her descendants. David ha'Melech's decree prohibited even the descendants of the Nesinim from becoming part of the Jewish people. The result of his decree was that even marriage with a descendant of a converted Nasin constitutes a violation of the Torah commandment of "Lo Sischaten." Accordingly, when Rashi here mentions the decree of David ha'Melech, he does not mean that the Nesinim are prohibited only mid'Rabanan, but rather that their descendants are prohibited mid'Oraisa since they never had the opportunity to become full-fledged Jews. (This explanation is consistent with the opinion of Rashi in Sanhedrin that Nesinim indeed are prohibited mid'Oraisa by the prohibition of "Lo Sischaten.")
The Pnei Yehoshua cites support for this explanation from the words of Rashi in Yevamos. Rashi there (78b, DH David) explains that the verse, "And the Giv'onim are not from the children of Yisrael" (Shmuel II 21:2), means that the Nesinim are not fit to become members of the Jewish people. Moreover, Rashi in Yevamos (79a, DH me'Chotev) writes that the Nesinim "are not included in [the category of] Yisrael, and they are not considered converts." What is the intent of Rashi's apparent repetitiveness? The Pnei Yehoshua suggests that Rashi there means as follows: "They are not included in Yisrael" refers to the first generation of Giv'onim that converted. "They are not considered converts" refers to their offspring born afterwards, who are not considered valid converts due to the decree of David ha'Melech. (See ME'IRI here and the RA'AVAD cited by the CHIDUSHEI HA'RAMBAN in Yevamos 78b. The Pnei Yehoshua was not in possession of those commentaries but nevertheless merited to reach the same conclusion as they did. See also CHIDUSHEI CHASAM SOFER here.) (D. BLOOM) (See Insights to Yevamos 76:2.)

29b----------------------------------------29b

2) THE PENALTY FOR RAPING A MINOR
QUESTION: The Mishnah lists girls ("Na'aros") for whom a man is fined even though he is prohibited from marrying them. The Gemara questions why a man who rapes or seduces such Na'aros is fined. The Torah obligates the rapist either to pay a fine or to marry his victim, but the Na'aros listed in the Mishnah are prohibited from marrying into the Jewish people. The verse states, "And she will be to him for a wife" (Devarim 22:29), which implies that the requirement to marry his victim (or to pay a fine) applies only to a girl who is fit to be his wife. It should not include the Na'aros listed in the Mishnah. Since the man cannot fulfill the requirement to marry his victim, he also should be exempt from the fine.
Reish Lakish answers that the two words "Na'arah" and "ha'Na'arah" in the verses teach three separate categories of Na'aros to whom one must pay a fine: a Na'arah whom one is permitted to marry, a Na'arah whom one is prohibited from marrying due to a Lo Ta'aseh, and a Na'arah whom one is prohibited from marrying due to an Isur Kares.
RASHI explains that the first occasion of the word "Na'arah" in the verse (22:28) teaches the law with regard to a man who rapes a Na'arah whom he is permitted to marry. In the verse that follows, the word "ha'Na'arah" seems extra: "He shall give to the father of the Na'arah..." (22:29) -- the verse could have said instead, "He shall give to the father," without the word "ha'Na'arah." The extra word "Na'arah" teaches the law in the second case, in which a man rapes a Na'arah whom he is prohibited from marrying due to a Lo Ta'aseh. The extra prefix "the" ("Ha") in the word "ha'Na'arah" teaches the law in a case in which a man rapes a Na'arah whom he is prohibited from marrying due to an Isur Kares.
If the Torah teaches that a man must pay a fine even when he rapes a Na'arah whom he is prohibited from marrying, why does the Torah state in the first place, "And she will be to him for a wife"? That verse implies that one is fined only when he rapes a Na'arah whom he is permitted to marry. If the Torah would have omitted that verse, it would have had no need to write the extra word "ha'Na'arah" to include even Na'aros whom he is forbidden from marrying.
ANSWERS:
(a) TOSFOS (DH v'Chad) answers that the verse, "And she will be to him for a wife," is necessary for a different reason, as the Gemara later (39b) describes. The verse does not teach that the man must pay a fine only when he is permitted to marry the Na'arah. Rather, it teaches that he may marry the Na'arah only with her consent. She is entitled to refuse to marry him if she so chooses. RASHI (39b, DH Tiheyeh) writes that the word "Tiheyeh" implies that she must "make herself be" to him. (The term "Mehavah" implies marriage through Kidushin, as the Gemara later (46b) derives from the verse, "She will marry (v'Hayesah) another man" (Devarim 24:2). As a formal legal transaction, Kidushin takes effect only with the consent of both parties.) Since the verse which teaches the requirement for consent also implies that a man is required to pay a fine only when the Na'arah is permitted to him in marriage, it is necessary for the Torah to write "ha'Na'arah" in the next verse to include Na'aros whom the man is not permitted to marry.
(b) REBBI AKIVA EIGER explains that the verse, "And she will be to him for a wife," is necessary for a different reason. Rebbi Meir maintains that one who rapes or seduces a Ketanah (a girl under the age of twelve) pays no fine. Rav Chisda (40b) explains that this law is derived from the word "Tiheyeh": the Torah fines the man only when his victim is old enough to accept Kidushin (to be "Mehavah" herself). The verse excludes a man who rapes a Ketanah from the requirement to pay a fine, since a Ketanah is unable to accept Kidushin for herself. Rebbi Akiva Eiger adds that even the Chachamim -- who disagree with Rebbi Meir and maintain that a man who rapes a Ketanah is fined even though the Ketanah cannot accept Kidushin -- maintain that the verse is needed to teach a different Halachah. The verse is needed to teach that one who rapes a Shifchah (maidservant) is not fined (see Mishnah, 29a) unless she was emancipated when she was under the age of three years and one day, after which time he had relations with her.
One might ask that if Rebbi Meir exempts a man from a fine when he rapes a girl who is not old enough to accept Kidushin for herself, why does he not argue with the Mishnah which imposes a fine on a man who rapes a Na'arah whom he is prohibited from marrying due to an Isur Kares? A Na'arah who is forbidden to him with an Isur Kares is like a Ketanah, as no bond of Kidushin takes effect with her.
Rebbi Akiva Eiger answers that although neither a Ketanah nor the Na'aros listed in the Mishnah are able to marry the man, the Na'aros who are forbidden to him with an Isur Kares nevertheless are able to marry other men, and therefore the fine applies to one who rapes them. In contrast, a Ketanah is unable to marry any man.
Do the Chachamim, who maintain that a man who rapes a Ketanah is fined even though the Ketanah cannot accept Kidushin, also maintain that a man who rapes a Shifchah is fined? Rebbi Akiva Eiger suggests that they agree that a man who rapes a Shifchah is not fined. The difference between a Ketanah and a Shifchah is that although the Ketanah cannot accept Kidushin for herself, her father can accept Kidushin on her behalf and marry her off. In contrast, the Shifchah is absolutely unable to accept Kidushin. Therefore, the Chachamim maintain that the fine applies to a Ketanah but not to a Shifchah, as derived from the verse, "And she will be to him for a wife." (D. BLOOM)

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