KA ʿB AL-AḤBĀR (Abū Isḥāq Ka ʿb al-AḤbār or "Kaʿb of-the Jewish-doctors"; also Ka ʿb al-Ḥabr , "Kaʿb the former Jewish doctor"; d. ca. 654), Jewish Yemenite convert to Islam from the tribe of Ḥimyar who lived in Ḥims (Homs). He was referred to as "the owner of the two books" (dhūl-kitābayni, i.e., the Koran and the Bible).
Some say that he converted to Islam in Muhammad's lifetime at the hands of the latter's cousin, ʿAli ibn Abī Ṭālib, while others say that he converted at the hands of the caliph Abu Bakr. But the most widespread version has it that he converted during the caliphate of *Omar ibn al-Khattab at the hands of Muhammad's uncle al-ʿAbbas, thus becoming the latter's mawlā or client. He is supposed to have been one of Omar ibn al-Khattab's closest advisors. Under ʿUthmānibn ʿAffān Kaʿb was a salaried preacher (qāṣās). He allegedly legitimized for ʿUthmān the borrowing of money from the treasury, on which an opponent of this caliph commented by saying: "You son of two Jewish parents, will you teach us our religion?" A polemical account associates the recent convert Kaʿb with Jewish scholars: in a meeting that took place in Jerusalem, Kaʿb resorted to a book found in Daniel's tomb in Susa in order to convince 42 Jews to embrace Islam; the then governor of Syria and Palestine, Muʿāwiya ibn Abī Sufyān, later included them among those entitled to an annual pension from the treasury.
Kaʿb's reputation as an expert in "sacred books" was an asset for the rulers who employed him to convey messages in their favor and to combat opposition movements. Supposed quotations from the "Torah" or the "Tales about Prophets," in addition to eschatological traditions, were used to indoctrinate the masses in general and the warriors in particular. Kaʿb reportedly died on his way to an expedition against Byzantium; one assumes that he was a battlefield preacher rather than a warrior.
Widespread accounts describe Kaʿb as providing Omar with the background necessary for Islamizing the Temple Mounṭ. For example, he bribed a Jewish ḥabr or doctor to pinpoint the rock on which Solomon had stood upon the completion of the Temple (or "the mosque"). However, in several anecdotes Kaʿb is accused of an attempted "Judaization" of nascent Islam by combining the directions of prayer of Moses and Muhammad. He argued that while praying in Jerusalem in the direction of Mecca, a Muslim had to direct himself at the same time to the Rock. Omar established the correct Muslim direction by praying toward Mecca with his back to the Rock. It was another famous Jewish convert, Abdallah ibn Salam, who confirmed that this had been the original direction before it was changed by the Jews. Omar in turn declared Abdallah more truthful than Kaʿb.
"Kaʿb," in: Ibn ʿAsākir, Taʾrīkh madīnat Dimashq, ed. L. al-ʿAmrawī, 151–76; B. Chapira, "Légendes bibliques attribuées a Kaʿb el-Ahbar," in: Revue des Études Juives, 69 (1919), 86–107; 70 (1920), 37–43; D.J. Halperin and G.D. Newby, "Two Castrated Bulls: A Study in the Haggadah of Kaʿb al-Aḥbār," in: jasor, 102 (1982), 631–38; M. Perlmann, "A Legendary Story of Kaʿb al-Aḥbār's Conversion to Islam," in: The Joshua Starr Memorial Volume (1953), 85–99; idem, "Another Kaʿb al-Aḥbār Story," in: jqr, 45 (1954), 48–58; M. Schmitz, "Kaʿb al-Aḥbār," in: eis, 2 (1927) 582b–583b; abridged version in: eis2 4 (1978), 316–317 (includes bibliography).
[Michael Lecker (2nd ed.)]