Jewish poet of Medina and an implacable enemy of Mohammed. His father was an Arab of the family of Nabhan (a branch of the tribe of Ṭayy), but his mother was a Jewess of the Banu al-Naḍir. His father having died early, Ka'b was brought up in his mother's family and in her faith. Tradition relates that at one time he confessed Islam, and even turned his face in prayer toward Mecca. After Mohammed's victory over the Meccans at Badr, Ka'b is supposed to have exclaimed that the interior of the earth would be pleasanter than its surface. He composed poems bewailing the defeat of the Meccans and exciting the Ḳuraish to revenge, but not all of these poems are properly authenticated.
It is but natural that Moslem authors should ascribe many evil deeds to their arch-enemy; their veracity is, however, questionable. Ka'b was charged with having maintained sinful relations with the wives of various Moslems, and with having gone to Mecca to induce the Ḳuraish to fight Mohammed once more. The latter, in order to nullify Ka'b's influence, hurled against him the following passage: "Recite to them the history of him to whom we have given our signs, but who turned away from them; had he wished, we would have exalted him thereby, but he crouched upon the earth and followed his own desire. He is likened unto a dog, which, if thou drivest him away, hangeth out his tongue, and if thou leavest him, hangeth out his tongue likewise" (Koran, vii. 174-175). There are two allusions to Ka'b in this passage; the first is contained in the reference to one possessing God's "signs" (i.e., the Bible), the second in the word "kalb " (dog), which by alliteration suggests the name of the poet. Since he refused to be frightened, Mohammed asked his friends: "Who will rid me of the son of Ashraf?" One of them, Mohammed b. Maslamah, declared himself ready to murder Ka'b, but asked permission to tell a falsehood; this was readily granted. The murderer and two accomplices entered Ka'b's house under a pretext and murdered him. His death was bewailed in several poems by the Jewish poet Sammak, who described him as a man ever faithful to his word and never guilty of treachery. The expulsion of the Banu al-Naḍir followed soon after Ka'b's death.
- Ibn Hisham, Waḳidi, and other sources;
- Hirschfeld, New Researches into the Composition and Exegesis of the Qoran, p. 116.