GEZERTA, term used by the geonim for the oath of imprecation that they instituted in place of the oath by God's name or
The gezerta was not instituted through a special geonic enactment (takkanah) but was based mainly on the geonic practice of evading oaths by God's name or kinnuy and replacing it by an oath of biblical imprecation – a process which may date back to the talmudic period. This explains the prevalence in geonic sources of phraseology such as "it is our custom," "they were accustomed to…," in relation to the gezerta; terminology attesting to enactment is used only in relation to the ceremony accompanying the imposition of gezerta: "They enacted that rams' horns should be brought and blown in the presence of the deponent, and he is threatened as well with excommunication and other decrees" (Ḥemdah Genuzah, ibid.).
The geonim suspended the administration of biblical and mishnaic oaths because of the increased taking of false oaths and disrespect for oaths, as well as the talmudic principle that punishment for a false oath applies to the entire world (TB, Shevu. 39b) – an explanation offered by many geonim. As Rav Natronai writes: "But now, because of the deceivers… the courts refrained from imposing oaths [sworn] on a Torah scroll,… and the courts saw that people were swearing false oaths and bringing calamity upon the world, they refrained from imposing the biblical oath and abolished it entirely" (see Ḥemdah Genuzah #22, and further responsa in, e.g., Teshuvot ha-Geonim [Assaf], 1927, p. 97, etc.). Rav Saadiah Gaon writes in his commentary to the Torah (Ḥayyei Sarah, ed. Zucker, p. 412): "…In our nation they did not discontinue swearing this oath, that is, by the Lord God of heaven and earth, until there were many who swore falsely, and earlier authorities abolished the oath by God's name, because they knew that punishment might be visited upon the entire world. They then began to administer the oath of imprecation, punishment for which is imposed only upon the person who swears, [and we follow] their tradition to this day." Similarly, Rav Hai Gaon (Mishpetei Shevu'ot, p. 11) writes: "Our rabbis are now accustomed not to administer the oath by God's name, for the entire world may suffer and the punishment for [violation] is severe.…" The imprecation was a useful substitute for the oath, because of the use of a curse and an imprecation was taken more seriously, in addition to the power of excommunication and the accompanying ceremony to deter people from lying: "Wherever a person is required to swear a biblical oath, he is now made to hold a Torah scroll… and inflated water skins are brought, as well as a bier on which the dead are borne… and lighted candles… and wood ashes… and sacks are placed in the center… and a ram's horn is blown together with the imprecation" (responsum by Rav Sherira and Rav Hai, Teshuvot ha-Geonim [Assaf], 1927, #3; see also responsum by Rav Paltoi, Gaon of Pumbedita, in Teshuvot ha-Geonim [Lyck], #10). Perhaps, moreover, it was in view of the prevalent use by the Muslims of oaths in God's name – they in fact refer in their writings to the Jewish oath – that the geonim were motivated to avoid a formula similar to that used in the Muslim oath.
The renunciation of oaths and their replacement by imprecation did not affect the actual obligation to take an oath, which was still considered as having biblical force, as declared by Rav Sherira Gaon in a responsum (Sha'arei Ẓedek, p. 71a, #3). The basic elements of the administration of oaths were not abandoned, and the imprecation "inherited" the various practices involved, such as holding an object (generally a Torah scroll) while swearing. These practices were still the hallmark of biblical (and mishnaic) oaths as against later rabbinic oaths (such as the "consuetudinary oath"), in which the Torah scroll was held not by the deponent but by the person administering the oath (the scroll might also be placed on a chair; see, e.g., Teshuvot ha-Geonim [Harkavy], #550). The gezerta also retained certain other elements of the oath, such as naming the suspicious party, answering "amen," etc.
The identification of the oath with the imprecation known as gezerta may be attributed to Saadiah Gaon. He cites a series of passages from the Bible to stress that the gezerta was not innovated by the geonim but could already be found in biblical tradition. This was indeed Saadiah's tendency in other contexts as well – to demonstrate that everything was rooted in the Bible, in order to reject Karaite criticism of the Rabbanite approach (see, e.g., Sha'arei Ẓedek 41b, #38). Saadiah makes systematic use of gezerta in connection with oaths of biblical force (such as the oath imposed on a defendant who admits part of a claim, or the oath required to rebut the evidence of a single witness), and mishnaic oaths (such as the oath of a widow or of partners). The identification of the oath with imprecation around the time of Saadiah enabled the geonim to innovate the institution of ḥerem setam, which was imposed when there was no obligation to administer an oath.
The provisions of the gezerta as instituted by the geonim were accepted in their time by communities outside Babylonia (Iraq) as well. In the transitional period between the geonim and the later rabbis, the gezerta still continued in use, though without its ceremonial accoutrements, in the Jewish centers of North Africa (R. Hananel), Spain (R. Joseph b. Abitur, R. Isaac Alfasi), and even Italy (R. Kalonymus and Meshullam b. Kalonymus), France, and Germany (R. Gershom Me'or ha-Golah, R. Judah ha-Kohen (author of Sefer ha-Dinim), Rashi, R. Eliezer b. Nathan of Mainz, R. Isaac the Elder), as implied by the works of the major authorities of those countries. However, as time passed, a marked change is observed in rabbinical literature. The gezerta with its special practices became increasingly rare, until it was virtually abandoned and the use of real oaths (by God's name or kinnuy) was resumed, even in regard to the post-mishnaic oath (shevu'at hesset). The change is first evident in Spain and Provence, as follows from the writings of Naḥmanides, R. Shelomo b. Adret, R. Yom Tov b. Abraham Ishbili, R. Isaac bar Abba Mari (author of Sefer ha-'Ittur), R. Abraham b. David of Posquières, and others, continuing later, around the end of the 13th century, in Germany and France. In Germany and France, however, when oaths by God's name or kinnuy were discontinued, the rule requiring an object to be held and the "amen" response during the administration of the oath were also almost completely abolished. When the use of oaths was resumed, there was still no requirement to hold an object while taking the oath. The early rabbis of Spain, where the oath by God's name (or kinnuy) had been resumed, found it necessary to permit the defendant to request that a ḥerem setam be imposed upon the plaintiff, lest the latter unnecessarily demand that an oath be administered to the former. In contemporary Franco-Germany, however, where the use of God's name in oaths had not yet been resumed, there was no need for such protection of the defendant. Only later do we find a return to oaths by God's name in France and Germany and, consequently, the possible imposition of ḥerem setam upon the plaintiff.
G. Libson, "Gezerta and Herem Setam in the Gaonic and Early Medieval Periods" (Heb.; dissertation, Hebrew University, Jerusalem 1979); idem, "The Use of a Sacred Object in the Administration of a Judicial Oath," in: Jewish Law Association Studies, 1 (1985), 53–60; B. Lifshitz, "Evolution of the Court-Oath with Imprecation," in: Shenaton ha-Mishpat ha-Ivri, 11–12 (1984–86), 393–406 (Heb.); H. Tykocinski, The Geonic Ordinances (Heb.; 1959).