Zadok (Isaac) Bar Mar Yishi
ZADOK (Isaac) BAR MAR YISHI
ZADOK (Isaac) BAR MAR YISHI (Ashi ) (also known as Mar Zadok ), gaon of Sura 816–818. Only a few of Zadok's responsa have been preserved, but most of his decisions, halakhic judgments, and ordinances, for example, the imposition of an oath upon a defendant who denies a claim on land (takkanot shevu'ah al kefirat karka'ot), were handed down by his successors in the gaonate. The geonim speak of Zadok with much reverence, *Amram, for instance, calling him "our master, who enlightens us." *Naḥshon Gaon was his son.
H. Tykocinski, Takkanot ha-Ge'onim (1959), 58–59; Abramson, Merkazim, 2.