יבמות כב

יבמות כב

הָנָךְ תַּרְתֵּי דְּדָמְיָין לַהֲדָדֵי כַּחֲדָא חָשֵׁיב לְהוּ, וְהָא שִׁיתַּסְרֵי. וְהָא מִכׇּל מָקוֹם לְדִידִי חַזְיָין לַן דִּכְתִיבָן לְאִיסּוּרָא! אֲמַר לֵיהּ: וְלִיטַעְמָיךְ, אִי הֲוָה כְּתִיב לְהֶיתֵּירָא, מִי הֲוֵות סָמְכַתְּ עֲלַיְיהוּ? דְּמָר בְּרֵיהּ דְּרַבְנָא מִי חֲתִים עֲלַיְיהוּ? הַשְׁתָּא נָמֵי דִּכְתִיב לְאִיסּוּרָא — לָאו מָר בְּרֵיהּ דְּרַבְנָא חֲתִים עֲלַיְיהוּ.

Those two, the wife of a father’s father’s brother and the sister of a father’s father, are similar to each other and are counted as a single case, and so there are sixteen. The Gemara restates Rav Hillel’s challenge to Ameimar’s opinion: But in any case I myself saw them written as prohibited. Rav Ashi said to Rav Hillel: And according to your reasoning, if in the list it was written that they were permitted, would you have relied on that? Is the signature of Mar, son of Rabbana, signed on it? Although you saw the list, you don’t know for certain who wrote it. Now too, that it is written that they are prohibited, the same holds true; the signature of Mar, son of Rabbana, is not signed on it, and so it cannot be relied upon to reject the opinion of Ameimar.

תָּנֵי דְּבֵי רַבִּי חִיָּיא: שְׁלִישִׁי שֶׁבִּבְנוֹ וְשֶׁבְּבִתּוֹ וְשֶׁבְּבֶן אִשְׁתּוֹ וְשֶׁבְּבַת אִשְׁתּוֹ — שְׁנִיָּה. רְבִיעִי שֶׁבְּחָמִיו וְשֶׁבַּחֲמוֹתוֹ — שְׁנִיָּה.

§ One of the Sages of the school of Rabbi Ḥiyya taught: The third generation from one’s son and one’s daughter, i.e., one’s great-grandchildren, and the third generation from his wife’s son and his wife’s daughter, i.e., one’s wife’s great-grandchildren, are all forbidden as secondary forbidden relationships. So too, the fourth generation from his father-in-law and from his mother-in-law, i.e., his wife’s great-grandmothers, are prohibited as secondary forbidden relationships.

אֲמַר לֵיהּ רָבִינָא לְרַב אָשֵׁי: מַאי שְׁנָא לְמַעְלָה דְּקָחָשֵׁיב לָהּ לְאִשְׁתּוֹ, וּמַאי שְׁנָא לְמַטָּה דְּלָא קָחָשֵׁיב לָהּ לְאִשְׁתּוֹ? לְמַעְלָה, דְאִיסּוּרָא מִכֹּחַ אִשְׁתּוֹ קָא אָתֵי — חָשֵׁיב לַהּ, לְמַטָּה, דְאִיסּוּרָא לָאו מִכֹּחַ אִשְׁתּוֹ קָאָתֵי — לָא קָחָשֵׁיב לַהּ.

Ravina said to Rav Ashi: What is different between the generations above, referring to his wife’s great-grandmothers, such that the Sage counts his wife as one of the generations and refers to them as the fourth generation, and what is different with regard to the generations below, referring to his great-granddaughters, such that he did not count his wife and referred to them as only the third generation? The Gemara answers: When counting above, the prohibition stems from his wife, as they are not his blood relatives but his wife’s. Therefore, she is counted. When counting below, however, the prohibition does not stem from his wife, as they are his own blood relatives, and so she was not counted.

וְהָא בֶּן אִשְׁתּוֹ וּבַת אִשְׁתּוֹ, דְּאִיסּוּרָא מִכֹּחַ אִשְׁתּוֹ קָאָתֵי, וְלָא חָשֵׁיב לַהּ! אַיְּידֵי דִּתְנָא שְׁלֹשָׁה דּוֹרוֹת לְמַטָּה דִּידֵיהּ וְלָא חַשְּׁבַהּ, תְּנָא נָמֵי שְׁלֹשָׁה דּוֹרוֹת לְמַטָּה דִּידַהּ וְלָא חַשְּׁבַהּ.

The Gemara objects: But he includes the granddaughter of his wife’s son and his wife’s daughter in his list of those forbidden due to his wife, yet he does not count her and refer to this as the fourth generation. The Gemara answers: Since he already taught three generations below himself, i.e., his own great-granddaughter, and there he did not count from his wife because it is his own blood relative, he taught three generations below his wife and did not count her. Instead, he referred to her great-granddaughter also as three generations below to maintain the uniform style of his words.

אֲמַר לֵיהּ רַב אָשֵׁי לְרַב כָּהֲנָא: שְׁנִיּוֹת דְּבֵי רַבִּי חִיָּיא, יֵשׁ לָהֶן הֶפְסֵק אוֹ אֵין לָהֶם הֶפְסֵק?

Rav Ashi said to Rav Kahana: Do those secondary forbidden relationships taught by one of the Sages of the school of Rabbi Ḥiyya have a conclusion, or do they not have a conclusion? Are those specified cases alone forbidden, or are all generations above and below also forbidden?

תָּא שְׁמַע, דְּאָמַר רַב: אַרְבַּע נָשִׁים יֵשׁ לָהֶם הֶפְסֵק, וְתוּ לָא. דִּלְמָא כִּי קָאָמַר רַב — לְהַהִיא מַתְנִיתָא. תָּא שְׁמַע: שְׁלִישִׁי וּרְבִיעִי. שְׁלִישִׁי וּרְבִיעִי — אִין, טְפֵי — לָא! דִּלְמָא מִשְּׁלִישִׁי וְאֵילָךְ, מֵרְבִיעִי וְאֵילָךְ.

Come and hear that which Rav said: Four women have a conclusion. This implies that it is only these four and no more. The Gemara rejects this: Perhaps when Rav said this he was referring only to the relationships listed in the baraita and not to all cases of secondary relationships. The Gemara suggests: Come and hear from the baraita itself, which states: The third generation from his son and his daughter and the fourth generation from his father-in-law and mother-in-law. This implies that with regard to the third and the fourth generations, yes, they are forbidden; but more than that, no. The Gemara rejects this: Perhaps this means from the third onward and from the fourth onward. The Gemara does not resolve this issue.

אֲמַר לֵיהּ רָבָא לְרַב נַחְמָן: חֲזִי מָר הַאי מֵרַבָּנַן דַּאֲתָא מִמַּעְרְבָא וְאָמַר, בְּעוֹ בְּמַעְרְבָא: גָּזְרוּ שְׁנִיּוֹת בְּגֵרִים, אוֹ לֹא גָּזְרוּ שְׁנִיּוֹת בְּגֵרִים?

§ Rava said to Rav Naḥman: Did the Master see this one of the Sages who came from the West, Eretz Yisrael, who said: In the West they asked whether the Sages issued a decree prohibiting secondary forbidden relationships for converts, or whether they did not issue a decree prohibiting secondary forbidden relationships for converts?

אֲמַר לֵיהּ: הַשְׁתָּא וּמָה עֶרְוָה גּוּפַהּ, אִי לָאו ״שֶׁלֹּא יֹאמְרוּ בָּאִין מִקְּדוּשָּׁה חֲמוּרָה לִקְדוּשָּׁה קַלָּה״, לָא גְּזַרוּ בְּהוּ רַבָּנַן — שְׁנִיּוֹת מִיבַּעְיָא?!

Rav Naḥman did not answer whether he had seen this Sage, but said to him: Now, with regard to all the forbidden relationships themselves, were it not for the fact that if converts would find that as Jews they were permitted to enter into relationships that were forbidden to them as gentiles and would say that they went from a state of more stringent sanctity as gentiles to a state of lesser sanctity as Jews, then the Sages would not have decreed to prohibit these relationships. Without the rabbinic decree it would have been permitted for a convert to marry even a close female relative, even his twin sister, who also converted. This is because a convert has the legal status of a newborn, with no family ties. Is it necessary to state that the Sages did not extend that decree to include secondary forbidden relationships? The purpose of the rabbinic prohibitions is to protect the Torah prohibitions, but in the case of converts this particular Torah prohibition does not apply.

אָמַר רַב נַחְמָן: גֵּרִים, הוֹאִיל וַאֲתוֹ לְיָדָן, נֵימָא בְּהוּ מִלְּתָא: אַחִין מִן הָאֵם — לֹא יָעִידוּ, וְאִם הֵעִידוּ עֵדוּתָן עֵדוּת. אַחִין מִן הָאָב — מְעִידִין לְכַתְּחִלָּה. אַמֵּימָר אָמַר: אֲפִילּוּ אַחִין מִן הָאֵם נָמֵי מְעִידִין לְכַתְּחִלָּה.

Rav Naḥman said: Since the issue of converts and their relatives has come to hand and is the topic of discussion, let us say a matter of halakha: Maternal half brothers who both convert may not testify together as a pair of witnesses before the court, but if they did testify, their testimony is valid. Although blood relatives are invalid as witnesses, converts are considered as though they have no relations. Paternal half brothers who both convert may testify together ab initio, since the halakha does not consider paternal half brothers of gentiles to be true relatives. Ameimar said: Even maternal half brothers may also testify together ab initio.

וּמַאי שְׁנָא מֵעֲרָיוֹת? עֶרְוָה — לַכֹּל מְסוּרָה, עֵדוּת — לְבֵית דִּין מְסוּרָה, וְגֵר שֶׁנִּתְגַּיֵּיר כְּקָטָן שֶׁנּוֹלַד דָּמֵי.

In what way is this case different from forbidden relations, where a convert may not marry his maternal sister due to rabbinic decree? The halakhot of forbidden relations are handed over to all, and every individual chooses his own wife. Therefore, the Sages issued a decree to prevent confusion between the status of a convert and that of a born Jew. However, testimony is handed over to the court, and the court knows to distinguish between the status of a born Jew and that of a convert. And the legal status of a convert who just converted is like that of a child just born, and all previous family ties become irrelevant.

מַתְנִי׳ מִי שֶׁיֵּשׁ לוֹ אָח מִכׇּל מָקוֹם — זוֹקֵק אֶת אֵשֶׁת אָחִיו לְיִבּוּם, וְאָחִיו הוּא לְכׇל דָּבָר, חוּץ מִמִּי שֶׁיֵּשׁ לוֹ אָח מִן הַשִּׁפְחָה וּמִן הַגּוֹיָה. מִי שֶׁיֵּשׁ לוֹ בֵּן מִכׇּל מָקוֹם — פּוֹטֵר אֵשֶׁת אָבִיו מִן הַיִּבּוּם, וְחַיָּיב עַל מַכָּתוֹ וְעַל קִלְלָתוֹ, וּבְנוֹ לְכׇל דָּבָר, חוּץ מִמִּי שֶׁיֵּשׁ לוֹ בֵּן מִן הַשִּׁפְחָה וּמִן הַגּוֹיָה.

MISHNA: In the case of anyone who has a brother of any kind, that brother creates a levirate bond causing his yevama to be required to perform levirate marriage if the first brother dies childless. And he is his brother in all respects, except for one who has a brother born from a Canaanite maidservant or from a gentile woman, as these do not have the legal status of brothers. Similarly, in the case of anyone who has a child of any kind, that child exempts his father’s wife from levirate marriage, since his father did not die childless. And that child is liable to receive capital punishment if he strikes his father or curses him. And he is his child in all respects, except for whoever has a child born from a Canaanite maidservant or from a gentile woman, as these do not have the halakhic status of children.

גְּמָ׳ מִכׇּל מָקוֹם לְאֵתוֹיֵי מַאי? אָמַר רַב יְהוּדָה: לְאֵתוֹיֵי מַמְזֵר. פְּשִׁיטָא, אָחִיו הוּא! מַהוּ דְּתֵימָא, לֵילַף אַחְוָה אַחְוָה מִבְּנֵי יַעֲקֹב: מָה לְהַלָּן — כְּשֵׁרִין וְלֹא פְּסוּלִין, אַף כָּאן — כְּשֵׁרִין וְלֹא פְּסוּלִין, קָא מַשְׁמַע לַן.

GEMARA: The Gemara asks: With regard to the statement that a brother of any kind causes his yevama to be required to perform levirate marriage, what additional case does this come to add? Rav Yehuda said: This adds the case of a mamzer, who, notwithstanding his status, is considered a brother. The Gemara wonders: But isn’t that obvious? He is his brother. The Gemara explains: This is necessary lest you say: Let us derive a verbal analogy between the word “brother” stated in the verse with regard to levirate marriage and “brother” stated with regard to the children of Jacob. Just as there, Jacob’s children are of unflawed lineage and not of flawed lineage and are not mamzerim, so too here, one might think that only brothers of unflawed lineage and not brothers of flawed lineage, i.e., mamzerim, obligate the yevama in levirate marriage. Therefore, this teaches us that a mamzer is considered a brother for the purposes of levirate marriage.

וְאֵימָא הָכִי נָמֵי? כֵּיוָן דִּלְעִנְיַן יִבּוּם מִיפְטַר נִפְטָר,

The Gemara asks: And say that is indeed the halakha. Perhaps a brother who is a mamzer does not obligate his yevama in levirate marriage. The Gemara answers: Since with regard to levirate marriage, if the husband had a child who was a mamzer he would exempt the wife from levirate marriage,

מִיזְקָק נָמֵי זָקֵיק.

the husband’s brother also causes a levirate bond with his yevama even if he is a mamzer.

וְאָחִיו הוּא לְכׇל דָּבָר. לְמַאי הִלְכְתָא? לְיוֹרְשׁוֹ וְלִיטָּמֵא לוֹ.

§ The mishna stated that he is his brother in all respects. The Gemara asks: With regard to what halakha was this said? The Gemara answers: To inherit from him, and to become ritually impure for him if he is a priest, as a brother is one of the relations for whom a priest is permitted to become ritually impure by attending his funeral.

פְּשִׁיטָא, אָחִיו הוּא! סָלְקָא דַּעְתָּךְ אָמֵינָא: הוֹאִיל וּכְתִיב: ״כִּי אִם לִשְׁאֵרוֹ הַקָּרוֹב אֵלָיו״, וְאָמַר מָר: ״שְׁאֵרוֹ״ — זוֹ אִשְׁתּוֹ, וּכְתִיב: ״לֹא יִטַּמָּא בַּעַל בְּעַמָּיו לְהֵחַלּוֹ״, יֵשׁ בַּעַל שֶׁמִּטַּמֵּא וְיֵשׁ בַּעַל שֶׁאֵין מִטַּמֵּא, הָא כֵּיצַד? מִטַּמֵּא הוּא לְאִשְׁתּוֹ כְּשֵׁרָה, וְאֵין מִטַּמֵּא לְאִשְׁתּוֹ פְּסוּלָה,

The Gemara asks: Isn’t this obvious, as he is his brother? The Gemara answers: It might enter your mind to say that a priest does not become impure for his brother of flawed lineage, since it is written with regard to priests: “None shall defile himself for the dead among his people except for his kin, that is near unto him” (Leviticus 21:1–2), and the Master said “his kin”; this is his wife, and a priest may defile himself for his wife. But it is written: “He shall not defile himself, being a husband among his people, to profane himself” (Leviticus 21:4), implying that he may not defile himself for his wife. This apparent contradiction is resolved as follows: There is a husband who does become impure for his wife, and there is a husband who does not become impure. How so? He becomes impure for his wife if she was fit and was permitted to a priest, but he does not become impure for his wife if she was unfit to marry a priest.

הָכִי נָמֵי: מִטַּמֵּא הוּא לְאָח כָּשֵׁר, וְאֵין מִטַּמֵּא לְאָח פְּסוּל — קָא מַשְׁמַע לַן. וְאֵימָא הָכִי נָמֵי? הָתָם לְאַפּוֹקֵי קָיְימָא, הָכָא אָחִיו הוּא.

So too, one might have thought that a priest becomes impure for a brother who is of unflawed lineage and not a mamzer, but he does not become impure for a brother of flawed lineage. Therefore, this comes to teach us that he does become impure for a brother who is a mamzer. The Gemara asks: Say this also, that by the same reasoning by which a priest may not become impure for a wife who was unfit for him, he may not become impure for an unfit brother either. Just as he does not become impure for an unfit wife, he should not become impure for an unfit brother? The Gemara answers: The two cases are different, as there, with regard to the unfit wife, she stands to be dismissed, since according to Torah law unfit women must be divorced. For this reason he does not become impure for her. Here, he is his brother.

חוּץ מִמִּי שֶׁיֵּשׁ לוֹ אָח מִן הַשִּׁפְחָה וּמִן הַגּוֹיָה. מַאי טַעְמָא? אָמַר קְרָא: ״הָאִשָּׁה וִילָדֶיהָ תִּהְיֶה לַאדוֹנֶיהָ״.

§ The mishna says: Except for whoever has a brother born from a Canaanite maidservant or from a gentile woman, as in these cases he is not considered a brother. The Gemara asks: What is the reason for this halakha? The Gemara answers: The verse states with regard to a Jewish slave who has children with a Canaanite maidservant: “The wife and her children shall be her master’s” (Exodus 21:4). This means that the children also have the status of Canaanite slaves, which implies that the lineage of a Canaanite maidservant’s child comes from the mother and not from the father.

מִי שֶׁיֵּשׁ לוֹ בֵּן מִכׇּל מָקוֹם פּוֹטֵר וְכוּ׳. ״מִכׇּל מָקוֹם״ לְאֵתוֹיֵי מַאי? אָמַר רַב יְהוּדָה: לְאֵיתוֹיֵי מַמְזֵר. מַאי טַעְמָא — דְּאָמַר קְרָא: ״וּבֵן אֵין לוֹ״ — עַיֵּין עָלָיו.

The mishna states: With regard to anyone who has a son of any kind, that son exempts his father’s wife from any levirate bond. The Gemara asks: What is added by the phrase: Of any kind? Rav Yehuda said: It adds a child who is a mamzer. What is the reason that a mamzer exempts a woman from any levirate bond? As the verse states with regard to levirate marriage: “And he has no [ain lo] child” (Deuteronomy 25:5). The phrase ain lo can be understood as ayyen alav, meaning investigate him. That is to say, investigate whether he is indeed childless, because any child, even a mamzer, exempts the widow from a levirate bond.

וְחַיָּיב עַל מַכָּתוֹ. אַמַּאי? קְרִי כָּאן: ״וְנָשִׂיא בְעַמְּךָ לֹא תָאוֹר״, בְּעוֹשֶׂה מַעֲשֵׂה עַמְּךָ!

It states in the mishna that a child who is a mamzer is liable to receive punishment if he strikes his father or curses him. The Gemara asks: Why should he be liable? Read here the verse: “You shall not curse a ruler of your people” (Exodus 22:27), which is interpreted to imply that the prohibition against cursing applies only to one who acts according to the deeds of your people. However, this father must have engaged in sexual relations with a woman who was forbidden to him in order to have a child who is a mamzer. Therefore, he did not act according to the deeds of the people. In that case, why should this son be liable to receive punishment for hitting him or cursing him?

כִּדְאָמַר רַב פִּנְחָס מִשְּׁמֵיהּ דְּרַב פָּפָּא: בְּעוֹשֶׂה תְּשׁוּבָה, הָכָא נָמֵי כְּשֶׁעָשָׂה תְּשׁוּבָה.

The Gemara answers: As Rav Pineḥas said in the name of Rav Pappa with regard to a different matter: This is referring to one who performs repentance. Here too, it is referring to one who performed repentance after the mamzer was born. He is thereafter considered to be living in accordance with halakha, and so his mamzer son is liable to receive punishment for cursing him.

וְהַאי בַּר תְּשׁוּבָה הוּא? וְהָתְנַן: שִׁמְעוֹן בֶּן מְנַסְיָא אוֹמֵר: אֵיזֶהוּ ״מְעֻוָּות לֹא יוּכַל לִתְקוֹן״ — זֶה הַבָּא עַל הָעֶרְוָה וְהוֹלִיד מִמֶּנָּה מַמְזֵר! הַשְׁתָּא מִיהָא עוֹשֶׂה מַעֲשֵׂה עַמְּךָ הוּא.

The Gemara objects: Is he in fact able to repent after fathering a mamzer? Didn’t we learn in a mishna that Shimon ben Menasya says: Which is: “That which is crooked cannot be made straight” (Ecclesiastes 1:15)? This is referring to one who engaged in intercourse with a relative who is forbidden to him and fathered a mamzer with her. This implies that he has no possibility of achieving total repentance. The Gemara responds: At least now, after repenting, he is considered as one who acts according to the deeds of your people. Although he cannot totally rectify his transgression, his child is liable to receive punishment for cursing or hitting him.

תָּנוּ רַבָּנַן: הַבָּא עַל אֲחוֹתוֹ, וְהִיא בַּת אֵשֶׁת אָבִיו — חַיָּיב מִשּׁוּם אֲחוֹתוֹ וּמִשּׁוּם בַּת אֵשֶׁת אָבִיו. רַבִּי יוֹסֵי בֶּן יְהוּדָה אוֹמֵר: אֵינוֹ חַיָּיב אֶלָּא מִשּׁוּם אֲחוֹתוֹ בִּלְבַד, וְלֹא מִפְּנֵי בַּת אֵשֶׁת אָבִיו.

§ The Sages taught: He who unwittingly engages in sexual relations with his sister, who is the daughter of his father’s lawful wife, is liable and must bring two sin-offerings. He must bring one sin-offering because she is his sister and another because she is the daughter of his father’s wife, which is mentioned in a separate verse in the Torah. Rabbi Yosei ben Yehuda says: He is liable only because she is his sister alone, and not because of the prohibition against engaging in sexual relations with the daughter of his father’s wife.

מַאי טַעְמַיְיהוּ דְּרַבָּנַן? אָמְרִי, מִכְּדֵי כְּתִיב: ״עֶרְוַת אֲחוֹתְךָ בַת אָבִיךָ אוֹ בַת אִמֶּךָ״, ״עֶרְוַת בַּת אֵשֶׁת אָבִיךָ מוֹלֶדֶת אָבִיךָ אֲחוֹתְךָ הִיא״ לְמָה לִי? שְׁמַע מִינַּהּ לְחַיְּיבוֹ מִשּׁוּם אֲחוֹתוֹ וּמִשּׁוּם בַּת אֵשֶׁת אָבִיו.

The Gemara asks: What is the reason for the opinion of the Rabbis, the first tanna of the baraita? They said: Since it is written in the Torah: “The nakedness of your sister, the daughter of your father, or the daughter of your mother…you shall not uncover” (Leviticus 18:9), then why do I need the verse: “The nakedness of your father’s wife’s daughter, begotten of your father, she is your sister…you shall not uncover” (Leviticus 18:11)? Conclude from this that the additional verse serves to make him liable separately due to the fact that she is his sister and due to the fact that she is his father’s wife’s daughter.

וְרַבִּי יוֹסֵי בְּרַבִּי יְהוּדָה, אָמַר קְרָא: ״אֲחוֹתְךָ הִיא״. מִשּׁוּם אֲחוֹתוֹ אַתָּה מְחַיְּיבוֹ, וְאִי אַתָּה מְחַיְּיבוֹ מִשּׁוּם בַּת אֵשֶׁת אָבִיו.

And Rabbi Yosei, son of Rabbi Yehuda, says: The verse states: “She is your sister,” which comes to limit and emphasize that you hold him liable due to the fact that she is his sister but you do not hold him liable a second time due to the fact that she is also his father’s wife’s daughter.

וְרַבָּנַן, הַאי ״אֲחוֹתְךָ הִיא״ מַאי עָבְדִי לֵיהּ? מִיבְּעֵי לְהוּ לְחַיְּיבוֹ עַל אֲחוֹתוֹ בַּת אָבִיו וּבַת אִמּוֹ, לוֹמַר שֶׁאֵין מַזְהִירִין מִן הַדִּין.

The Gemara asks: And what do the Rabbis do with this verse: “She is your sister”? They require it in order to hold him liable to receive punishment for having relations with his sister who is both the daughter of his father and the daughter of his mother, to say that the Sages do not derive an additional Torah prohibition by way of a logical derivation, i.e., an a fortiori inference. In other words, although it would seem that since he is liable to receive punishment for having relations with his father’s daughter and also for his mother’s daughter, this must be all the more true in a case where she is the daughter of both his father and his mother, yet nevertheless, there is no new prohibition here. Therefore, the matter was taught explicitly in the Torah, to teach that the Sages may not derive additional prohibitions by way of a fortiori inferences.

וְרַבִּי יוֹסֵי בְּרַבִּי יְהוּדָה: אִם כֵּן, לִכְתּוֹב רַחֲמָנָא ״אֲחוֹתְךָ״, ״הִיא״ לְמָה לִי? מִשּׁוּם ״אֲחוֹתְךָ״ אַתָּה מְחַיְּיבוֹ, וְאִי אַתָּה מְחַיְּיבוֹ מִשּׁוּם ״בַּת אֵשֶׁת אָבִיו״.

And Rabbi Yosei, son of Rabbi Yehuda, says: If so, that the matter was written for this purpose, then the Merciful One should have written only: Your sister. Why do I need the phrase “she is”? This limits the halakha and teaches that for unintentional intercourse with his sister who is also his father’s wife’s daughter you hold him liable because she is his sister; you do not additionally hold him liable because she is his father’s wife’s daughter.

וְרַבָּנַן: אַף עַל גַּב דִּכְתִיב ״אֲחוֹתְךָ״, אִיצְטְרִיךְ לְמִכְתַּב ״הִיא״, שֶׁלֹּא תֹּאמַר בְּעָלְמָא מַזְהִירִין מִן הַדִּין,

And how do the Rabbis interpret the additional phrase “she is”? Although “your sister” is written, it was necessary to write “she is” so that you not say that generally the Sages may derive additional prohibitions by way of a logical derivation, i.e., an a fortiori inference.

וְכִי תֵּימָא: ״אֲחוֹתְךָ״ דִּכְתַב רַחֲמָנָא לְמָה לִי? מִילְּתָא דְּאָתְיָא בְּקַל וְחוֹמֶר, טָרַח וְכָתַב לַהּ קְרָא — כְּתַב רַחֲמָנָא ״הִיא״.

The Gemara explains how this principle is derived from the text. As, if you would say: Why do I need the term “your sister” that the Merciful One writes in the Torah, since it is possible to derive this by a fortiori inference and it therefore appears redundant? The answer is that the Torah wrote this apparently redundant term to teach the principle that with regard to a matter that could be derived by means of an a fortiori inference, the verse unnecessarily wrote it explicitly. The Merciful One writes the term “she is” in order to teach that just as in this case the Sages may not derive additional prohibitions by way of an a fortiori inference, so too, in all other cases they may not derive additional prohibitions that are not stated in the text.

וְרַבִּי יוֹסֵי בְּרַבִּי יְהוּדָה: אִם כֵּן, לִיכְתְּבֵיהּ רַחֲמָנָא לַ״אֲחוֹתְךָ הִיא״ בְּאִידַּךְ קְרָא.

And Rabbi Yosei, son of Rabbi Yehuda, says: If this is the reason for the verse, then let the Merciful One write: She is your sister, in the other verse, which states: “The nakedness of your sister, the daughter of your father, or the daughter of your mother,” and not in the verse that speaks of the daughter of one’s father’s wife.

וְרַבִּי יוֹסֵי בְּרַבִּי יְהוּדָה, הַאי ״בַּת אֵשֶׁת אָבִיךָ״ מַאי עָבֵיד לֵיהּ? מִיבְּעֵי לֵיהּ: מִי שֶׁיֵּשׁ לוֹ אִישׁוּת לְאָבִיךָ בָּהּ, פְּרָט לַאֲחוֹתוֹ מִשִּׁפְחָה וְגוֹיָה, שֶׁאֵין אִישׁוּת לְאָבִיךָ בָּהּ.

The Gemara asks: And what does Rabbi Yosei, son of Rabbi Yehuda, do with this verse, which states: “The daughter of your father’s wife” (Leviticus 18:9)? He requires it to teach that one is liable only for relations with a half-sister whose mother is someone with whom there is a possibility of forging marital ties with your father, even if she was not in actuality his wife. This comes to exclude his sister from a Canaanite maidservant or a gentile woman, with whom your father cannot have marital ties, since betrothal does not take effect with these women.

וְאֵימָא: פְּרָט לַאֲחוֹתוֹ מֵאֲנוּסָה? הַהִיא לָא מָצֵית אָמְרַתְּ מִדְּרָבָא,

The Gemara asks: So say: “Your father’s wife’s daughter” comes to teach specifically the case of a daughter from a woman married to his father, thereby excluding from the definition of: His sister, his sister from a woman who had been raped. Perhaps if she was born of a woman who was not married to his father she would not be considered his sister. The Gemara answers: You cannot say that due to the reason said by Rava.

דְּרָבָא רָמֵי, כְּתִיב: ״עֶרְוַת בַּת בִּנְךָ אוֹ בַת בִּתְּךָ לֹא תְגַלֶּה״, הָא בַּת בְּנָהּ דִּידַהּ וּבַת בִּתָּהּ דִּידַהּ שְׁרֵי, וּכְתִיב: ״עֶרְוַת אִשָּׁה וּבִתָּהּ לֹא תְגַלֵּה אֶת בַּת בְּנָהּ וְאֶת בַּת בִּתָּהּ״, הָא כֵּיצַד?

As Rava raised a contradiction: In one verse it is written: “The nakedness of your son’s daughter, or of your daughter’s daughter, you shall not uncover” (Leviticus 18:10), which implies, consequently, that her son’s daughter or her daughter’s daughter is permitted. And it is written elsewhere: “You shall not uncover the nakedness of a woman and her daughter; you shall not take her son’s daughter or her daughter’s daughter” (Leviticus 18:17), which states explicitly that her son’s daughter and daughter’s daughter are prohibited. How can these texts be reconciled?

כָּאן בָּאוֹנָסִין, כָּאן בְּנִשּׂוּאִין.

Here, it is referring to a daughter by a woman whom one raped, in which case he is allowed to marry her daughter provided she is not also his daughter. There, it is referring to a woman whom one married, in which case it is forbidden to marry her daughter under any circumstances. However, even in a case where one’s father raped a woman, one is still permitted to marry the woman’s daughter by another man. If one’s father had a daughter with this woman, one would be prohibited from having a relationship with that daughter, as she is his paternal half-sister.