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Isaac ben Sheshet Perfet


ISAAC BEN SHESHET PERFET (known as Ribash from the initials of R abbi I saac B en Sh eshet; 1326–1408), Spanish rabbi and halakhic authority. Perfet was born in Barcelona, where he studied under such eminent scholars as *Pereẓ ha-Kohen, Ḥasdai b. Judah Crescas (the grandfather of the philosopher), and *Nissim b. Reuben Gerondi, and where he later acted unofficially as rabbi. In 1370, Isaac, together with Nissim and five other Jewish notables, was arrested on a false charge and imprisoned for several months. After acquittal, he moved to Saragossa, where he accepted the position of rabbi, only to be involved in the first of the many controversies and family tragedies that were to embitter his career. In Saragossa he made strenuous efforts to secure the abolition of certain objectionable customs. He did not succeed, but brought upon himself the opposition of the local scholars. Finally he decided to leave for Calatayud but was persuaded to change his mind. Faced with continued disharmony in the community, he moved to Valencia, where from 1385 he acted as rabbi.

The anti-Jewish riots of 1391 drove him to North Africa. A close reading of the Valencia court records reveals that the authorities asked Perfet to convert as a way to stop the riots. After he refused, they trumped up a charge against him that would have resulted in his death unless he converted. This time Perfet relented and he converted, thereby becoming a Marrano. He was baptized on July 4, 1391, which was the Ninth of Av. A year and a half later, he managed to leave Valencia for North Africa and resume his life as a Jew. A number of his responsa deal with the issue of those compelled to convert to Christianity. After a short stay at Miliana, he finally settled in Algiers, where he was enthusiastically welcomed. Fresh vexations awaited him; however, as another refugee, jealous of Isaac's prestige, launched a violent campaign against the newcomer in the hope that he would leave Algiers. Thanks to the intervention of *Saul Astruc ha-Kohen, the civil authorities put an end to the conflict by appointing Isaac dayyan or communal rabbi. Their action, however, antagonized a celebrated refugee from Majorca, Simeon b. Ẓemaḥ *Duran, who declared the appointment invalid, no government having the power of jurisdiction in Jewish communal affairs. Duran relented when he was convinced that Isaac harbored no thoughts of personal aggrandizement, and the latter was left free to enjoy general affection and respect in his last years. On the anniversary of his death pilgrimages were made to his tomb until recent years.

Perfet's most important work is his responsa (Constantinople, 1546). They exercised considerable influence on subsequent halakhah, and were one of the pillars upon which the Shulḥan Arukh rested. They contain a vast amount of halakhic material – part derived from sources which are no longer extant – together with much valuable information about popular customs in Spain and North Africa. The collection is of very great importance for knowledge of the history of the Jews in those countries in the 14th century. Perfet was involved as a halakhist and decisor in the great controversy connected with the French chief rabbinate (see *Trèves (Trier)); he was one of the first to discuss the status of *Marranos from the halakhic point of view, which had become one of the crucial problems of Spanish and North African Judaism. He was one of those who established the minhag of Algiers regarding the financial rights connected with matrimonial law. Perfet recognized five categories of minhag: (a) Those acts that are halakhically acceptable but deemed prohibited by custom, thus creating a defensive "fence" around the Torah; (b) those acts that are halakhically acceptable but which certain communities deemed prohibited by custom; (c) a prohibitive custom based on one opinion in a rabbinic dispute; (d) those behaviors that are not customs but for which the sages avowed that whoever acts in such a way will be blessed; and (e) when a person errs thinking that what he does is correct. Perfet argued that one cannot change the custom in categories (a) through (c). However, the last two categories do not constitute minhag and can therefore be changed. On three occasions, Perfet accepted customs based on Islamic customs (see responsa nos. 94, 158, 102, and 148). In each case, the practice was not in violation of halakhah and thus acceptable.

Perfet also wrote an extensive commentary on several talmudic tractates, and a commentary on the Pentateuch. Poems and kinot composed by him were published in Ẓafenat Pa'ne'aḥ (1895). His work shows some knowledge of philosophy, even though he opposed its study and regarded the philosophical preoccupations of *Maimonides and *Levi b. Gershom with misgiving. He also dissociated himself from the Kabbalah. The responsa She'elot u-Teshuvot ha-Ribash ha-Ḥadashot (Munkacs, 1901) are not all his.


A.M. Hershman, Rabbi Isaac bar Sheshet Perfet and his Times (1943), Hebrew edition (1956); H.J. Zimmels, Marranen in der rabbinischen Literatur (1932), 24, 91ff.; Baer, Spain, index; I. Epstein, Responsa of R. Simon b. Zemach Duran (1930), index. add. bibliography: J. Slotnik, "Rabbi Yizhak bar Sheshet – ha-Rivash" (diss., Touro, 2001); D. Yarden, in: Sefer Zikaron le-Yizhak Ben-Zvi 1 (1964); M. Slay, in: Shanah be-Shanah (1971), 226–36; idem, in: Maḥanayim, 1 (1991), 158–61; Z. Rayrah, in: Sefunot, 17 (1983), 11–20; M. Kellner, in: Tradition, 15 (1975), 110–18; E. Seroussi, at:

[Hirsch Jacob Zimmels /

David Derovan (2nd ed.)]

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