Bava Batra

"nor infer [any law] from it" — because a judge must be guided only by that  which his eyes see. Raba inquired: What  [is the law in the case of] a person in good health?  Does R. Johanan b. Beroka  speak [only] of [the case of] a dying man, who has the right to appoint an heir [on the spot],  but not [of] one [who is] in good health; or [does he] perhaps [speak] also even of one in good health? — R. Mesharsheya said to Raba: Come and hear: R. Nathan said to Rabbi,  'You  have taught your Mishnah  in accordance with [the views of] R. Johanan b. Beroka; for we learnt:  [A husband who] did not give [his wife] in writing  [the following statement, viz.], "The male children that will be born from our marriage  shall inherit  the money of thy marriage settlement in addition to their shares with their brothers",  is [nevertheless] liable, because it is a condition  laid down by the court'.  And Rabbi replied [to him]:  "We learnt: they shall take".  [Later], however, Rabbi stated: "It was childishness on my part to be presumptuous in the presence of Nathan the Babylonian. The fact is  that the law is well established [that] male children may not seize  any sold property [of their father in payment for their mother's kethubah]".  [Now], if it is assumed [that] we learnt, "they shall take", why may they not seize sold property?  Consequently it must be inferred that we learnt: "they shall inherit"'.  [Now], who has been heard to hold this view?  [Surely] R. Johanan b. Beroka! Thus it may be inferred [that the law  applies] even to [the case of] one who is in good health. R. Papa said to Abaye: Whether according to him who said, [that the reading  was] 'they shall take', or according to him who said [that the reading was], 'they shall inherit', [the question may be asked], surely one [has] not [the right] to give possession of something which is not yet in existence! And even R. Meir,  who maintains [that] one may give possession of that which is not yet in existence, applies this law  [only to the case where the possession was given] to one who is [already] in existence,  but not [to the case where possession is given] to one who does not exist.  [The reason], however,  [must be that] a condition [imposed] by a court is different [from an ordinary assignment],  here, likewise,  [it could have been explained  that] a condition [imposed] by a court is different!  — He replied to him: Because he [first] used the expression, 'they shall inherit'. Subsequently, Abaye said: What I said is nothing,  For we learnt:  [A husband who] did not give his wife in writing  [the following] undertaking, viz., 'The female children that will be born from our marriage  shall live in my house and be maintained out of my estate until they shall be taken [in marriage] by men, is [nevertheless] liable, because that [fatherly duty] is a condition [imposed] by the court. Consequently, this  is a case of giving to one as a 'gift'  and to another as an 'inheritance',  and wherever [something is given] to one person as an inheritance and to another as a gift  even the Rabbis agree [that the assignments are valid]. R. Nihumai (one said, it was R. Hananya b. Minyumai) asked Abaye: