PROSBUL (Heb. פרוזבול or פרוסבול), a legal formula whereby a creditor could still claim his debts after the *Sabbatical Year despite the biblical injunction against doing so (Deut. 15:2). The text of the prosbul reads, "I declare before you, so-and-so, the judges in such-and-such a place, that regarding any debt due to me, I may be able to recover any money owing to me from so-and-so at any time I shall desire." The pros-bul was signed by witnesses or by the judges of the court before whom the declaration was made (Shev. 10:4, Git. 36a). The principle underlying the prosbul was based on the passage "and this is the manner of the release: every creditor shall release that which he hath lent unto his neighbor; he shall not exact it of his neighbor and his brother… Of a foreigner thou mayest exact it; but whatsoever of thine is with thy brother thy hand shall release" (Deut. 15:2, 3). From this the law was deduced that the operation of the year of release did not affect debts of which the bonds had been delivered to the court (bet din) before the intervention of the Sabbatical Year (Shev. 10:2), since the Court was regarded as a corporate body to which the words "thy brother," suggesting an individual, did not apply. The court would therefore collect its debts after the Sabbatical Year (Yad, Shemittah ve-Yovel 9:15). Through a slight extension of this precedent, the prosbul was instituted, which in effect amounted to entrusting the court with the collection of the debt. Without actually handing over the bond to the court as previously required, the creditor could secure his debt against forfeiture by making the prescribed declaration.
The prosbul was instituted by Hillel. The Mishnah states that when he saw that the people refrained from giving loans one to another before the Sabbatical Year, thereby transgressing "Beware that there be not a base thought in thy heart," etc. (Deut. 15:9), he instituted the prosbul (Shev. 9:3). The Talmud therefore explained prosbul as pruz buli u-buti, meaning an advantage for both the rich and poor. It benefited the rich since it secured their loans, and the poor since it enabled them to borrow (Git. 37a). The word seems, however, to be an abbreviation of the Greek expression πρòς βουλῇ βουλευτῶν meaning "before the assembly of counselors" (cf. *Boule). The rabbis later explained that Hillel only abrogated the Mosaic institution of the release of all debts every seventh year since the law of release itself was only of rabbinic authority during the Second Temple period when the Jubilee was not operative because the land was not fully occupied by Israel (Git. 36a–b). It was only permitted to write a prosbul when the debtor possessed some real property from which the debt could be collected. The rabbis were very lenient with this rule, however, and permitted the writing of a prosbul even when the debtor possessed a minute amount of land such as a flowerpot or the trunk of a tree. The creditor was also permitted temporarily to transfer to the debtor a small parcel of land so that the prosbul could be written (Shev. 10:6, 7; Git. 37a). An antedated prosbul was considered valid, but a postdated one was void (Shev. 10:5).
During the Hadrianic persecutions, all religious practices were forbidden on the penalty of death and it was hazardous to preserve a prosbul. The rabbis therefore ruled that a creditor could collect his debt even if he did not produce a prosbul since it was assumed that he previously wrote one, but had destroyed it out of fear (Ket. 9:9). This temporary provision later became the established law, and the creditor was believed when he alleged that he had lost his prosbul (Git. 37b; Sh. Ar., Ḥm 67:33). Orphans were not required to execute one since they were considered wards of the court. Money owed to them was therefore automatically considered as being owed to the court (Git. 37a). The amoraim debated the virtue of Hillel's institution. Samuel declared that if he had the power he would abolish it, while R. Naḥman held that even if no prosbul was actually written it should have been regarded as written. Samuel also maintained that only the leading courts of each generation could supervise the writing of a prosbul. Subsequent practice, however, entrusted all courts with this responsibility (Git. 36b; Isserles to Sh. Ar., Ḥm 67:18). During the Middle Ages, the writing of prosbuls was widely disregarded since there was an opinion that the laws of the Sabbatical Years were no longer operative (Rema to Sh. Ar., Ḥm 67:1 and commentaries). Nevertheless, meticulous individuals continued to write prosbuls even in modern times (e.g., Pe'er ha-Dor: Ḥayyei Ḥazon Ish, 2:245; see also *Takkanot; *Usury).