The Ma’hari explains that a predated prosbul is one written before the shemittah year arrives – namely, at the end of Elul of the sixth year, which is the eve of Rosh Hashanah of the seventh year.All loans made prior to the execution of the prosbul are deemed collectible, with the proviso that the document is not destroyed, and remain valid for the entire seventh year, as shemittah only erases all loans at the end of the year.
If a person wrote and handed over a prosbul to a beit din at the conclusion of shemittah, which is the 29th of Elul right before Rosh Hashanah of the eighth year, it is valid. The document need only remain intact for that one day.If he destroyed the document afterwards, he may still collect his loan any time he wishes because the prosbul document was extant at the required time.
The Ma’hari points out that we see from the above that a prosbul is only effective when the loan precedes the document. If it comes after, the prosbul will not render the loan collectible. Therefore we write a prosbul at the end of the sixth year so that all loans of the six preceding years not be automatically canceled by shemittah.
Minchat Bikkurim (to the Tosefta in Shevi’it ad loc.) explains that since one does not want to be in violation of the rabbinical prohibition of “lo yigos” (pressuring one for repayment of a loan), it is proper to execute the prosbul prior to the seventh year.
Thus, any loans made during the seventh year with Hillel’s sanction would require a separate prosbul at the year’s conclusion.
(To be continued)