Yevamot — Daf 94b

לו ומותר בקרובות שניה ושניה מותרת בקרוביו ואם מתה ראשונה מותר בשניה

אמרו לו מתה אשתו ונשא את אחותה ואחר כך אמרו לו קיימת היתה ומתה הולד ראשון ממזר והאחרון אין ממזר ר' יוסי אומר כל שפוסל ע"י אחרים פוסל ע"י עצמו וכל שאין פוסל ע"י אחרים אינו פוסל ע"י עצמו:

גמ׳ ואע"ג דאזיל אשתו וגיסו למדינת הים דאהני הני נשואים דקמיתסרא אשת גיסו אגיסו אפ"ה אשת גיסו אסירא אשתו שריא ולא

אמרינן מתוך שנאסרה אשת גיסו אגיסו תיאסר אשתו עליו לימא מתניתין דלא כר"ע דאי ר"ע הויא לה אחות גרושתו

דתניא כל עריות שבתורה אין צריכות הימנו גט חוץ מאשת איש שנשאת על פי ב"ד ור"ע מוסיף אף אשת אח ואחות אשה וכיון דאמר ר"ע בעיא גט ממילא איתסרא עליה דהויא לה אחות גרושתו

ולאו איתמר עלה א"ר גידל א"ר חייא בר יוסף אמר רב האי אשת אח היכי דמי כגון שקדש אחיו את האשה והלך למדינת הים ושמע שמת אחיו ועמד ונשא את אשתו דאמרי אינשי הך קמא תנאה הוה ליה בקידושין והאי שפיר נסיב

והאי אחות אשה נמי היכי דמי כגון שקידש את אשה והלכה למדינת הים ושמע שמתה עמד ונשא את אחותה דאמרי אינשי הך קמייתא תנאי הוה ליה בקדושיה והא שפיר נסיב אלא נשואין מי איכא למימר תנאה הוה ליה בנשואין

אמר ליה רב אשי לרב כהנא אי ר' עקיבא ליתני נמי חמותו דהא שמעינן ליה לר"ע דאמר חמותו לאחר מיתה לאו בשרפה

דתניא (ויקרא כ, יד) באש ישרפו אותו ואתהן אותו ואת אחת מהן דברי ר' ישמעאל ר"ע אומר אותו ואת שתיהן

בשלמא לאביי דאמר משמעות דורשין איכא בינייהו דר' ישמעאל סבר חדא כתיב ור' עקיבא סבר תרתי כתיב שפיר

אלא לרבא דאמר חמותו לאחר מיתה איכא בינייהו ליתני נמי חמותו

אמר ליה נהי דמיעטה קרא משרפה מאיסורא מי מיעטה קרא

ותאסר בשכיבה דאחותה מידי דהוה אאשה שהלך בעלה למ"ה לא דמי אשתו דבמזיד אסירא מדאוריי' בשוגג גזרו בה רבנן

TO HIM;  AND HE IS PERMITTED TO MARRY THE RELATIVES OF THE SECOND WOMAN,  AND THE SECOND WOMAN IS PERMITTED TO MARRY HIS RELATIVES. IF THE FIRST DIED HE IS PERMITTED TO MARRY THE SECOND. IF HE WAS TOLD, HOWEVER, THAT HIS WIFE WAS DEAD, AND HE MARRIED HER SISTER, AND THEN HE WAS TOLD THAT SHE WAS THEN  ALIVE BUT HAD SINCE DIED, ANY CHILD BORN BEFORE  [HIS FIRST WIFE'S DEATH] IS A BASTARD, BUT ANYONE BORN AFTER THAT  IS NO BASTARD. R. JOSE STATED:  WHOSOEVER DISQUALIFIES FOR OTHERS DISQUALIFIES FOR HIMSELF AND WHOSOEVER DOES NOT DISQUALIFY FOR OTHERS DOES NOT DISQUALIFY FOR HIMSELF. GEMARA. Even though his wife and his brother-in-law  went to a country beyond the sea,  so that such marriage  had the effect of causing the prohibition of the wife of his brother-in-law to his brother-in-law, it is nevertheless the wife of his brother-in-law that is forbidden,  while his own wife is permitted.  and we do not say that, since the wife of his brother-in-law is forbidden to his brother-in-law, his Own wife also should be forbidden to him. Are we to assume that our Mishnah does not represent the view of R. Akiba? For if [it be in agreement with] R. Akiba [his wife]  would be the sister of his divorcee!  For it was taught: None of the women In incestuous marriages forbidden in the Torah require a letter of divorce,  except a married woman  who remarried in accordance with the decision of the Beth din.  R. Akiba, however, adds  also a brother's wife  and a wife's sister.  Now, since R. Akiba ruled that she  requires a letter of divorce, [his first wife] becomes ipso facto forbidden to him because she is the sister of his divorcee! Was not, however, the following statement made in connection with this  ruling: R. Giddal said in the name of R. Hiyya b. Joseph in the name of Rab, 'How is one to understand this "brother's wife"?  Where a man's brother, for instance, betrothed a woman and went to a country beyond the sea, and he,  on hearing that his brother was dead, married his wife;  since people might say  that the first  had attached a certain condition to the betrothal  and that the latter  had lawfully married her.  And how is one to understand a "wife's sister"?  Where a man, for instance, betrothed a woman and she went to a country beyond the sea, and he, on hearing that she died, married her sister;  since people might say  that he had attached a certain condition to the betrothal  of the first  and that he, therefore, legally married the other'.  In respect of marriage,  however, can it be said that one had attached a condition to marriage! Said R. Ashi to R. Kahana: If [our Mishnah represents the view of] R. Akiba, one's mother-in-law  should also be mentioned,  since R. Akiba was heard to state: [The marriage of] a man's mother-in.law after the death [of his wife] is not punishable by burning!  For it was taught: They shall be burnt with fire. both he and they,  he and one of them;  so R. Ishmael. R. Akiba said: He and both of them.  This presents no difficulty according to Abaye who explained that the difference between them  lies in the interpretation of the text,  R. Ishmael maintaining that the text mentioned only one  while R. Akiba maintains that the text spoke of two.  According to Raba, however, who explained that the difference between them  is [the case of marriage of] a man's mother-in-law after the death [of his wife].  his mother-in-law should also have been mentioned!  — The other replied: Granted that Scripture has excluded her  from the penalty of burning. has Scripture. however, excluded her from the prohibition? Let her,  however, be forbidden [to her husband] through his cohabitation with her sister, her case being similar to that of a woman whose husband went to a country beyond the sea!  — [The two cases are] not alike: His wife who, [if she had acted] presumptuously,  is forbidden to him by Pentateuchal law, has been forbidden to him, when [she acted] unwittingly, by a preventive measure of the Rabbis;