Bava Batra — Daf 128a

אתה נתתו לי במתנה רצונך השבע וטול ונשבע אינו יכול לחזור בו

מאי קא משמע לן תנינא אמר לו נאמן עלי אבא נאמן עלי אביך נאמנין עלי שלשה רועי בקר רבי מאיר אומר יכול לחזור בו וחכמים אומרים אינו יכול לחזור בו

הא קא משמע לן דבאתן לך מחלוקת והלכה כדברי חכמים:

שלח ליה רבי אבא לרב יוסף בר חמא הלכה גובין מן העבדים ורב נחמן אמר אין גובין

שלח ליה ר' אבא לרב יוסף בר חמא הלכה שלישי בשני כשר רבא אמר אף בראשון

מר בר רב אשי אכשר באבא דאבא ולית הלכתא כמר בר רב אשי

שלח ליה רבי אבא לרב יוסף בר חמא היה יודע לו בעדות קרקע עד שלא נסתמא ונסתמא פסול

ושמואל אמר כשר אפשר דמכוין מצרנהא אבל גלימא לא ורב ששת אמר אפי' גלימא אפשר דמכוין מדת ארכו ומדת רחבו אבל נסכא לא ורב פפא אמר אפי' נסכא אפשר דמכוין מדת משקלותיו

מיתיבי היה יודע לו בעדות עד שלא נעשה חתנו ונעשה חתנו פיקח ונתחרש פיתח ונסתמא שפוי ונשתטה פסול

אבל היה יודע לו בעדות עד שלא נעשה חתנו ונעשה חתנו ומתה בתו פיקח ונתחרש וחזר ונתפקח פיתח ונסתמא וחזר ונתפתח שפוי ונשתטה וחזר ונשתפה כשר

זה הכלל כל שתחלתו או סופו בפסלות פסול תחלתו וסופו בכשרות כשר

you gave him to me as a gift, [but] if you wish, take an oath  and you will get him back';  and [the first] took the oath; [the latter] is not allowed to retract.  What does he teach us?  [The obvious principle underlying the law] has [surely] been taught [elsewhere]:  [If one of the litigants] said to the other,  'I have full confidence  in my father,  I have full confidence in your father, I have full confidence in three oxherds',  R. Meir says, he may retract,  and the Sages say he may not!  He  teaches us this: That the dispute  [relates also to the case] where [a litigant declared], 'I will give it to you'  and [that] the halachah is in accordance with the words of the Sages. R. Abba sent to R. Joseph b. Hama: The halachah is that slaves may be seized [from orphans, in payment of a debt incurred by the father].  R. Nahman. however, said they may not be seized. R. Abba sent to R. Joseph b. Hama: The halachah is that [a relative in the] third [degree] is qualified [to act as witness for or against a relative] in the second [degree].  Raba said: Also [for, or against a relative] in the first [degree]  also. Mar, son of R. Ashi permitted [a grandson to act as witness] for his father's father. The law, [however], is not in accordance with [the view of] Mar, son of R. Ashi. R. Abba sent to R. Joseph b. Hama: If a person possessed evidence  in one's favour [in the matter of a plot of] land, before he became blind, and [then] became blind, he is disqualified.  Samuel, however, said: He is permitted [to give evidence], [since] it is possible for him to gauge [the extent of] its boundaries; but [in the case of] a cloak [he is] not [to be admitted as witness].  R. Shesheth said: Even [in the case of] a cloak [his evidence is admissible, for] it is possible for him gauge the measurements of its length and of its breadth; but not [in the case of] a bar of metal. R. Papa said: Even [in the case of] a bar of metal, [for] it is possible for him to gauge its weight. An objection was raised: 'If a person possessed evidence  affecting another before he became his son-in-law, and, [subsequently,] he became his son-in-law, [or if that witness] had the faculty of hearing and became deaf, the faculty of seeing and became blind, sane and became insane, he is disqualified [from giving evidence]. If, however, he possessed evidence affecting him before he became his son-in-law, and when he became his son-in-law, his daughter died; [or if he] had the faculty of hearing, became deaf, and regained his hearing; [or if he] had the faculty of Seeing, became blind, and regained his eyesight; [or if] he was sane, became insane, and regained his sanity, [in all these cases] he is qualified [to act as witness]. This is the general rule: Whenever his beginning  or his end  was under a disqualification, he is disqualified, [but whenever] his beginning and his end [find him] in a suitable condition, he is permitted [to give evidence].