He converted to Islam later in his life. Abu'l Barakat does not refer to his conversion in his writings, and the historical sources give contradictory episodes of his conversion. According to the various reports, he converted either out of "wounded pride", fear of the personal consequences of the death of Sultan Mahmud's wife while under his care as a physician or fear of execution when he was taken prisoner in a battle between the armies of the caliph and that of the sultan. Ayala Eliyahu argues that the conversion was "probably motivated by convenience reasons".