This study examines the intertextuality and cultural interdependence between the Qur'an, its exegesis (tafsīr), and Jewish and Christian traditions, with particular attention to the role of isrāʾīliyyāt in shaping early Islamic thought. Qurʾānic exegesis emerged within the religious and cultural milieu of late antiquity, engaging with pre-existing Jewish and Christian narratives to affirm, reinterpret, and reorient theological paradigms. The incorporation of isrāʾīliyyāt, derived from biblical, pseudepigraphical, and apocryphal sources, reflects the dynamic interplay between the Qurʾānic message and external traditions. While these elements enriched exegetical efforts, they also introduced a potential tension between the Qurʾān's transformative theological vision and a later tendency in tafsīr to revert to pre-Islamic interpretations. This study highlights how the early exegetical tradition negotiated this tension, illustrating a broader process of interreligious exchange and theological redefinition that underscores the reciprocal and multi-dimensional interactions between Islamic, Jewish, and Christian intellectual and textual traditions.