An impostor who, in the time of Muhammad, claimed the prophetic office. His name was ‘Aihalah ibn Ka’b, and he belonged to the tribe of ‘Aus, of which he was an influential chief He was surnamed Zu ‘l-Himar, or “The Master of the Ass,” (But another reading is Zu ‘l-Khimar or, “He with the veil.”) because he used frequently to say, “The master of the ass is coming unto me,” and pretended to receive his revelations from two angels named Suhaik and Shuraik: Being good hand at legeidemain, and having a smooth tongue, he gained mightily on the multitude by the strange feats which he shewed them, and the eloquence of his discourse. By these means he greatly increased his power, and having made himself master of Najran and the territory of Taif, on the death of Badhan, the governor of Yaman for Muhammad he seized that province also, killing Shahr, the son of Hadhan, and taking to wife his widow Azad whose father he had also slain. The news being brought to Muhammad, he sent to his friends and to the tribe of Hamdan, a party of whom conspiring with Qais ibn ‘Abd Yaghuth, who bore Aswad a grudge, and with Firuz and Aswad’s wife, broke by night into his house, where Firuz surprised him and cut off his head. While dying, it said that he roared like a bull, at which his guards came to the chamber door, but were sent away by his wife, who told them that the prophet was only agitated by the divine inspiration. This was done the very night before Muhammad died. The next morning the conspirators caused the following proclamation to be made viz. “I bear witness that Muhammad is the Apostle of God, and that ‘Aihala is a liar”; and letters were immediately sent away to Muhammad, with an account of what had been done; but a messenger from heaven outstripped them and acquainted the prophet with the news, what he imparted to his Companions a little before his death, the letters themselves not arriving till Abu Bakr was chosen Khalif. It is said that Muhammad on his occasion told those who attended him that before the Day of Judgment thirty more imposters, besides Musailimah and Aswad, should appear. The whole time from the beginning of Aswad’s rebellion to his death was four months.
Based on Hughes, Dictionary of Islam