Nissi (also Nīsī) ben Berekhiah al-Nahrāwanī was a scholar and liturgical poet in the late ninth and early tenth centuries. His name suggests a family origin either in the Persian town of Nahravan or in the town of al-Nahrawān in eastern Iraq. Nissi was one of the Jewish notables of Baghdad. His successful mediation of a dispute in 922 between the exilarch David ben Zakkay and the Pumbeditan gaon Mevasser ben Qimoy led Nathan the Babylonian (see Nathan ha-Bavlī) to describe him as a “miracle-worker,” clearly a pun on his given name. In 928, Ben Zakkay offered the gaonate to Nissi, who had been res…