In the medieval history of Islam in the western Mediterranean and Africa, Qāḍī ʿIyāḍ (1083–1149 CE) is an important legal scholar during the transition from the Almoravids (1040–1147) to the Almohads (1121–1269). His Kitāb al-shifāʾ, a work on the life of the prophet Muḥammad (d. 632), which has been preserved in hundreds of manuscripts, is to this day an extremely popular work with Muslim readers. Scholars such as Delfina Serrano, Maribel Fierro, and Javier Albarran have suggested that the Almoravid partisan Qāḍī ʿIyāḍ composed the Kitāb al-shifāʾ—perhaps during a short and difficult tenure as judge in Granada in 1136—as a polemical rebuttal of the Almohad claims that their leader Ibn Tūmart (b. between 1078 and 1081, d. 1130) was the mahdī (Ar. “rightly guided”), whose rule would precede the end of the world. But there is no evidence—whether documentary or anecdotal—about the origins of the Kitāb al-shifāʾ. Against this background, I am suggesting a change of perspective, from the lost story of the work’s composition to the remarkable success of its reception since the twelfth century. I hypothesize that a codicological analysis of Kitāb al-shifāʾ manuscripts during the course of the work’s circulation yields material and historical evidence for the evolution of Muslim approaches to Muḥammad’s life.