Bava Batra

— 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.