Russian Talmudist; lived in the second half of the eighteenth century. Together with his brother, Shabbetai Bishka, he wrote the "Shebet Aḥim" (The Brothers' Sitting), essays on different passages of the Talmud, with an appendix entitled "Shem 'Olam" (Eternal Name), being comments on different passages of the Haggadah and the Bible. The work was published (Wilna-Grodno, 1833) by his grandson, Joshua ben Kalonymus Cohen Ẓedeḳ, who added an appendix of his own Talmudic essays under the title "Naḥal Yabboḳ."