Bava Batra — Daf 157b

אלא הא מני ר' מאיר היא דאמר אדם מקנה דבר שלא בא לעולם

אמר רב יעקב מנהר פקוד משמיה דרבינא תא שמע שטרי חוב המוקדמין פסולין והמאוחרין כשרין

ואי סלקא דעתך דאיקני קנה ומכר דאיקני קנה והוריש לא משתעבד מאוחרין אמאי כשרין דאיקני הוא

הא מני רבי מאיר היא דאמר אדם מקנה דבר שלא בא לעולם

אמר רב משרשיא משמיה דרבא תא שמע לשבח קרקעות כיצד הרי שמכר שדה לחבירו והשביחה ובא בעל חוב וטרפה כשהוא גובה גובה את הקרן מנכסין משועבדין ואת השבח מנכסין בני חורין

ואי סלקא דעתך דאיקני קנה ומכר דאיקני קנה והוריש לא משתעבד בעל חוב אמאי גובה שבחא

הא מני ר' מאיר היא דאמר אדם מקנה דבר שלא בא לעולם

אם תמצא לומר דאיקני קנה ומכר דאיקני קנה והוריש לא משתעבד הא לא משתעבד אם תמצא לומר משתעבד לוה ולוה וחזר וקנה מהו לקמא משתעבד או לבתרא משתעבד

אמר רב נחמן הא מילתא איבעיא לן ושלחו מתם ראשון קנה רב הונא אמר יחלוקו וכן תני רבה בר אבוה יחלוקו אמר רבינא מהדורא קמא דרב אשי אמר לן ראשון קנה מהדורא בתרא דרב אשי אמר לן יחלוקו והלכתא יחלוקו

מיתיבי לשבח קרקעות כיצד הרי שמכר שדה לחבירו והשביחה ובא בעל חוב וטרפה כשהוא גובה גובה את הקרן מנכסין משועבדין ואת השבח מנכסין בני חורין ואם איתא חצי שבח מבעי ליה

מאי גובה נמי דקתני חצי שבח:

— But [the fact is that] this [Mishnah] represents the view of  R. Meir who holds [that] a person may transfer possession of something that is not [yet] in existence. R. Jacob of Nehar Pekod  said in the name of Rabina, Come and hear: Ante-dated bonds of indebtedness are invalid  and post-dated [ones] are valid.  Now, if it could be assumed [that where the bond contained the entry]. 'That I may acquire'. [and] he [subsequently] bought and sold [or where it contained the entry] 'That I may acquire' [and] he [subsequently] bought and transmitted [the purchase] as an inheritance, [the land] is not mortgaged, [to the creditor], why [are] post-dated [bonds] valid?  This [is surely similar to the case of an entry] 'That I may acquire'! — [But] this [may] represent the view of  R. Meir who holds [that] a person may transfer possession of something that is not [yet] in existence. R. Mesharsheya in the name of Raba said, Come and hear! How [is one to understand the statement that] for improvement of lands [one may not seize any sold property]? If [a person] has sold a field to another who improved it,  and a creditor [of the seller] came and seized it,  when [the buyer] collects [from the seller].  he collects [the value of] the principal [even] from mortgaged property, but [that of the] improvement from free  property [only].  Now, if it is assumed, that where [a bond of indebtedness contained the entry]. 'That I may acquire'. [and] the debtor bought [land] and sold [it, or where the bond contained the entry]. 'That I may acquire'. [and] he bought [land] and transmitted [it] as an inheritance, [that land is] not mortgaged [to the creditor], why does the creditor seize the improvement[s]?  — This [may] represent the view of  R. Meir who holds [that] a person may transfer possession of something that is not [yet] in the world. If [a good reason] could be found for the statement  [that where there was an entry in a bond of indebtedness], 'That I may acquire'.  [and the debtor subsequently] bought [land] and sold [it, or where the bond contained the entry]. 'That I may acquire',  [and the debtor subsequently] bought [land] and transmitted it as an inheritance, [that land is] not mortgaged [to the creditor, the question that follows does not arise], since [the land was] not [in any way] mortgaged. If, [however. a reason] could be found for the statement  [that such land]  is mortgaged [to the creditor, the question arises as to] what [is the ruling in the case where the debtor] borrowed [from one person].  and [then] borrowed [from another],  and then purchased [some real estate which he subsequently sold].  [Is this land] mortgaged to the first [lender],  or is it mortgaged to the second?  — R. Nahman replied: We [also] have raised the same  question,  and [a reply] was sent from Palestine  [that] the first acquired [the right of seizing that land]. R. Huna said: They  divide [the land among themselves].  And Rabbah b. Abbuha also learned [that the land] is to be divided [between them]. Rabina said: In the first version,  R. Ashi told us  [that] the first [creditor] acquired [the right over the land];  the second  version of R. Ashi [however], told us [that the land was] to be divided.  And the law is [that the land] is to be divided. An objection was raised: How [is one to understand the statement that] for improvement of lands [one may not seize any sold property]? If [a person] has sold a field to another who improved it, and a creditor [of the seller] came and seized it,  when [the buyer] collects [from the seller]  he collects [the value of] the principal [even] from sold property but [that of the] improvement from free  property [only]. Now, if that were so,  he  should [only be able to claim] half [the cost of his] improvement!  — [The expression]. 'he collects', which was used,  also implies half [the value of his] improvement.