Abraham ben Isaac of Narbonne (Hebrew: ר׳ אַבְרָהָם בֶּן יִצְחָק מִנַרְבּוֹנָה)(c. 1080-85 – 1158) was a Provençal rabbi, also known as Raavad II, and author of the halachic work Ha-Eshkol (The Cluster).
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.
Most scholars assume it is an intentional forgery by Auerbach, but Israel Ta-Shma, citing the agreement of Jacob Sussman, argues it was forged in the 13th century by Moses de León, the forger of the Zohar and many other books.
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 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.