Like most of the Provençal scholars, Raavad II was a diligent author, composing numerous commentaries upon the Talmud, all of which, however, have been lost with the exception of that upon the treatise Baba Batra, of which a manuscript has been preserved in Munich. Numerous quotations from these commentaries are to be found in the writings of Zerahiah Gerondi, Nahmanides, Nissim Gerondi, and others. Many of his explanations of Talmudical passages are also repeated in his responsa which give his method of treatment. In Abraham's comments on the Talmud he seems to have taken Rashi as his model; for they are marked by the same precision and clearness of exposition. An idea of his Talmudic knowledge may be gathered from his book Ha-Eshkol. This work was modeled after the well-known work of Isaac Alfasi, and was the first important attempt at a legal code made by the French Jews. It does not equal Alfasi's work either in originality or in depth, but it contained some noteworthy improvements upon its model, such as the arrangement of its contents according to subject-matter, which greatly facilitated its practical use. Raavad II also drew upon the Jerusalem Talmud and the gaonic literature much more fully than Alfasi, and treated at much greater length many subjects which were only briefly considered by Alfasi. His depth and acumen, however, are shown to much better advantage in his responsa, quoted in the collection Temim De'im and in the Sefer ha-Terumot of Samuel Sardi. Other responsa sent to Joseph ben Ḥen of Barcelona and Meshullam ben Jacob of Lunel are found in a manuscript belonging to Baron de Günzburg in Saint Petersburg. A collection of Raavad II's responsa preserved in Yemen, the only manuscript of its kind, was published by R. Yosef Qafih in 1962. As an acknowledged rabbinical authority and president of the rabbinical board, he was frequently called upon to give his decision on difficult questions: and his answers show that he was not only a lucid exegete, but also a logical thinker.
Impact
Though he lacked originality, Abraham's influence upon Talmudical study in Provence ought not to be underrated. Languedoc formed politically a connecting link between Spain and northern France; in like manner Jewish scholars played the rôle of intermediaries between the Jews of these countries. Abraham ben Isaac represented this function; he was the intermediary between the dialectics employed by the tosafists of France and the systematic science of the Spanish rabbis. The French-Italian codifiers – Aaron ha-Kohen of Lunel, Zedekiah ben Abraham, and many others – took Abraham's Ha-Eshkol for their model; and it was not until the appearance of the Tur that Ha-Eshkol lost its importance and sank into comparative oblivion. The school founded by Abraham ben Isaac, as exemplified in RABaD III and Zerahiah ha-Levi, was nevertheless the creator of a system of Talmudic criticism; and the method it employed was the tosafist dialectic modified and simplified by Spanish-Jewish logic.
