NISSIM BEN REUBEN GERONDI° (known from the acronym of Rabbenu Nissim as the RaN; ?1310–?1375), one of the most important Spanish talmudists. Nissim's family originated in Cordova and settled first in Gerona, where he is thought
Nissim's renown rests chiefly on his halakhic works. His method and system were solidly founded in accordance with the tradition of learning acquired from the school of Nahmanides, Solomon b. Abraham Adret, Aaron ha-Levi of Barcelona, and their contemporaries, and though his works contain many sayings of these scholars without naming them, he adapted their words, crystallized them, and added much of his own so that his works are among the best produced by this school of learning. One of his main works is a commentary on the halakhot of Isaac *Alfasi to the Talmud. It seems that all the parts of this work have been preserved, and all have been published on the margin of Alfasi's commentary beginning with its first printed editions down to the present day.
This commentary comprises the tractates Shabbat, Pesaḥim, Beẓah, Rosh Ha-Shanah, Yoma, Ta'anit, Megillah, Sukkah, Ketubbot, Gittin, Kiddushin, Shevu'ot, Avodah Zarah, Ḥullin, and Niddah. He also wrote novellae to the Talmud, of which up to the present the following have been published: Gittin (Constantinople, 1711), Niddah (Venice, 1741), Ḥullin to the end of chapter 8 (in: Ḥamishah Shitot, Sulzbach, 1762), Bava Meẓia (Dyhrenfurth, 1823), Shevu'ot (Venice, 1608, at the end of the responsa of Moses *Galante), Rosh Ha-Shanah (1871), Avodah Zarah (1888), Mo'ed Katan (1937), Bava Batra (1963), Eruvin (1969), and Pesaḥim (1970).
His commentary to the tractate Nedarim, which is his best-known work, is published in all the usual editions of the Talmud and serves as the standard commentary to this tractate instead of that of Rashi. Some of his novellae to the Talmud still remain in manuscript, but most of them have been repeatedly republished, since they are among the works most acceptable to scholars of all countries and times. His commentaries to Alfasi differ from those to the Talmud in that they aim at giving the halakhic ruling, and in fact they have no real literary connection with Alfasi, with whom he frequently disagrees. The novellae to tractates Megillah, Shabbat, Ketubbot, and Sanhedrin published under Nissim's name are not by him. They represent one of the most difficult problems connected with the study of Nissim's works and teachings, as it is definite that a generation and more before him there lived in Barcelona another scholar with the same acronym–RaN (whose personal name is not certain), and whose works to several talmudic tractates have been recently published. Only 77 of Nissim's responsa are extant (Rome, 1545; Constantinople, 15482 from a different manuscript; and thereafter in many editions); also a book of 12 sermons (Constantinople 15331 and frequently thereafter), of a decidedly anti-philosophical character, though written in the style of philosophical literature; and a commentary on the Pentateuch of which the section on Genesis has been published (1968). The publication of the commentary to the Pentateuch has removed the few doubts that remained among some scholars as to whether Nissim is the RaN of the book of sermons ascribed to him or whether they were perhaps written by the other scholar of the same name. Discernible in both these works is Nissim's strong desire to prove the superiority of prophecy and Bible over philosophy, and thereby to strengthen the people's faith and their spiritual ability to bear up during the difficult periods of persecution and polemics of those times. He also wrote piyyutim and poems, some of which have been preserved and published.
S. Assaf, Mekorot u-Meḥkarim be-Toledot Yisrael (1950), 173–81; A.M. Hershman, Rabbi Isaac ben Sheshet Perfet and his Times (1943), 192–6 and index; Baer, Spain, 2 (1966), index; S.H. Kook, Iyyunim u-Meḥkarim, 2 (1963), 321–4; L.A. Feldman (ed.), Shitah la-Ra-N… al Massekhet Ketubbot (1966) introd.; idem, in: Koveẓ al Yad, 7 (17; 1968), 125–60; idem (ed.), in: Nissim b. Reuven Gerondi, Perush al ha-Torah (1968), introd.; E. Hurwitz, in: Hadorom, 24 (1967), 39–87.