Yevamot

whence you were hewn  and to the hole of the pit  whence you were digged,  and this is followed by the text, Look unto Abraham your father, and unto Sarah that bore you. R. Nahman stated in the name of Rabbah b. Abbuha: Our mother Sarah was incapable of procreation; for it is said, And Sarai was barren; she had no child,  she had not even a womb. Rab Judah son of R. Samuel b. Shilath stated in the name of Rab: That  was taught only in respect of the early generations who lived many years. In respect of the later generations, however, whose years of life are few, only two years and a half, corresponding to three periods of pregnancy  [are allowed]. Rabbah stated in the name of R. Nahman: Three years [must elapse],  corresponding to three remembrances;  For a Master said: Sarah, Rachel and Hannah  were remembered on New Year's Day. Rabbah ruled: These general principles  are to be disregarded.  For consider: Who compiled our Mishnah? Rabbi, of course; but the years of life were already reduced in the days of David. For it is written, The days of our years are threescore years and ten. With regard to the assumption that 'it is possible that it was he who was unworthy to have children from her',  is it not possible that it was she who was unworthy?  — Since she is not commanded to fulfil the duty of propagation she is not so punished.  But surely it is not so!  For the Rabbis once said to R. Abba b. Zabda, 'Take a wife and beget children', and he answered them, 'Had I been worthy I would have had them from my first wife'! — There he was merely evading the Rabbis; for, in fact, R. Abba b. Zabda became impotent through the long discourses of R. Huna. R. Giddal became impotent through the discourses of R. Huna;  R. Helbo became impotent through the discourses of R. Huna,  and R. Shesheth also became impotent through the discourses of R. Huna. R. Aha b. Jacob was once attacked by dysuria,  and when he was supported on the college cedar tree a discharge issued like a green palm shoot. R. Aha b. Jacob stated: We were a group of sixty scholars, and all became impotent through the long discourses of R. Huna;  with the exception of myself who followed the principle, Wisdom preserveth the life of him that hath it. IF HE DIVORCED HER SHE IS PERMITTED etc. Only a second husband  but not a third;  whose view, then, is represented by our Mishnah? — It is that of Rabbi. For it was taught: If she circumcised her first child and he died,  and a second one who also died,  she must not circumcise her third child; so Rabbi. R. Simeon b. Gamaliel, however, said: She circumcises the third, but must not circumcise the fourth child. But, surely, the reverse was taught;  now which of these is the latter?  — Come and hear what R. Hiyya b. Abba stated in the name of R. Johanan: It once happened with four sisters at Sepphoris that when the first had circumcised her child he died; when the second [circumcised her child] he also died, and when the third [circumcised her child] he also died. The fourth came before R. Simeon b. Gamaliel who told her, 'You must not circumcise [the child]'.  But is it not possible that if the third sister had come he would also have told her the same!  — If so,  what could have been the purpose of the evidence of R. Hiyya b. Abba? [No]. It is possible that he meant to teach us the following: That sisters also establish a presumption! Raba said: Now that it has been stated that sisters also establish a presumption, a man should not take a wife either from a family of epileptics, or from a family of lepers. This applies. however, only when the fact had been established by the occurrence of three cases. What is the decision?  — When R. Isaac b. Joseph came he related: Such a case was once submitted to R. Johanan in the Synagogue of Ma'on  on the Day of Atonement which fell on a Sabbath. A woman, it happened, had circumcised her child  who died; her second [sister circumcised her child] and he also died, and her third sister appeared before him. He said to her, 'Go and circumcise him'. Said Abaye to him:  See, you have permitted  a forbidden  and a dangerous  act. Abaye, however, relying upon this statement  married Homa the daughter of Isi son of R. Isaac the son of Rab Judah, although Rehaba of Pumbeditha had married her and died, and R. Isaac son of Rabbah b. Hana had subsequently married her and also died. And after he had married her, he himself died also. Said Raba: Would any one else have exposed himself to such danger? Surely he himself had said that Abin was reliable  but that Isaac the Red was not a person to be relied upon;  that Abin was well acquainted with any change  [in the views of R. Johanan] but Isaac the Red was not acquainted with any such changes! Furthermore, it might be said that their dispute  extended only to the case of circumcision; do they, however, differ also in the case of marriage? — Yes; for so it was taught: If a woman was married to one husband  who died, and to a second one who also died, she must not be married to a third; so Rabbi. R. Simeon b. Gamaliel said: She may be married to a third, but she may not be married to a fourth. In the case of circumcision, one can well understand [why the operation is dangerous with some children and not with others] since the members of one family may bleed profusely  while those of another family may bleed little;  what, however, is the reason in the case of marriage?  — R. Mordecai answered R. Ashi: Thus said Abimi from Hagronia in the name of R. Huna, 'The source  is the cause'.  But R. Ashi stated: '[The woman's] ill luck is the cause'.  What practical difference is there between them?  — The difference between them is the case where the man only betrothed her and died,  or also when he fell off a palm-tree and died. SAID R. JOSEPH SON OF RABA to Raba: I enquired of R. Joseph whether the halachah is in agreement with Rabbi, and he replied in the affirmative. [I asked] whether the halachah is in agreement with R. Simeon b. Gamaliel, and he again replied in the affirmative. Was he thereby merely ridiculing me?' — The other replied: No; there are several anonymous statements [in the Mishnah] and he informed  you [that in the matter of] marriage and flogging [the anonymous Mishnah]  agrees with Rabbi, and that in the matter of menstrual periods and the ox [whose owner has been] fore-warned  [the anonymous Mishnah] agrees with R. Simeon b. Gamaliel. As to marriage, there is the statement just discussed.  'Flogging'? — As we learned: A man upon whom the penalty of flogging had been repeatedly inflicted is to be placed  under confinement  and fed on barley, until his stomach bursts. 'The menstrual periods'? — As we learned: A woman may not