The concept of prophetic infallibility ʿiṣma has seen significant development within Islamic theology, influenced by various narrative sources and theological discourses. This chapter delves into how early portrayals of prophets, which often mirrored Hebrew Bible narratives, depicted them as fallible beings capable of sin. These early depictions, frequently incorporating elements from isrāʾīliyyāt, posed challenges for later Islamic scholars who aimed to maintain the moral and spiritual perfection of prophets. This study pays particular attention to qiṣaṣ al-anbiyāʾ (Tales of the Prophets), especially the earlier versions by authors such as al-Kisa’ī and al-Thaʿlabī, which included isrāʾīliyyāt narratives that conflicted with the idealized Islamic image of prophets. These depictions starkly contrasted with later version by Ibn Kathīr that emphasized prophetic infallibility. Ultimately, the evolution of ʿiṣma underscores the dynamic interplay between narrative traditions and theological imperatives in the construction of Islamic prophetic models. Furthermore, isrāʾīliyyāt narratives posed a significant threat to the image of prophets in Islam, necessitating immediate responses from scholars to preserve this idealized image. By analyzing the perspectives of prominent theologians and exegetes such as al-Rāzī, al-Ghāzalī, and Ibn Kathīr, this study traces the transition from the acceptance of prophetic fallibility to a more rigid doctrine of infallibility.