In 1988, Rabbi Nosson Dovid Rabinowich published the first -ever translation of one of the most important primary sources for the history of the Talmudic and Gaonic Period, The Iggeres of Rav Sherira Gaon. Rav Sherira Gaon was Gaon of the Pumbeditha Yeshiva from 968-1006 c.e. At that time, the Yeshiva was located in Baghdad, as was the situation with its main competitor, the Yeshiva of Sura. Although Rav Sherira Gaon wrote many responsa and novellae to the Talmud (all collected and published in two volumes by Rabbi Nosson Dovid Rabinowich in 2013 in conjunction with Mossad Ha’Rav Kook), his crowing achievement, at the age of eighty-one, was the Epistle [Iggeres] sent to Rav Yaakov bar Nissim of Kairouan [Tunis]. The Iggeres was written in response to a series of fundamental questions presented by Rav Yaakov on behalf of the elders of his city, considered a major Torah center. The contribution of the Iggeres is, essentially, twofold:
- A detailed explanation of the methodology of Rabbinic legal literature with an appreciation of its many primary sources
- A systematic and chronological list of the bearers of tradition from the Members of the Great Assembly down to his own generation.