The present article examines the anti-Jewish polemics in a remarkable Christian Arabic treatise from the eleventh century, the heyday of Arabic culture: the Book of Sessions of Elias of Nisibis (975–1046), metropolitan of the Church of the East. In this treatise, Elias presents his discussions with his Muslim interlocutor, the vizier Abū l-Qāsim al-Maghribī (981–1027). The content of the disputations is transmitted in two substantially different versions: one of them is presented in the Book of Sessions, the other, in Elias’ Epistle to the vizier.