This interdisciplinary study investigates the mechanisms of social capital formation in the early Islamic community. The data comprises selected Qur'anic verses (Ḥujurāt, 10; Tauba, 103; Māʾida, 2; Anfāl, 63; Āl ʿImrān, 103), authoritative tafsīr, and historical references such as Ibn Hishām's Sīra. The research employs qualitative thematic content analysis; the verses and interpretations were coded, producing three central categories— Islamic brotherhood, social institutions, and reciprocal norms. These were compared with the social capital theory (trust, networks, norms). Findings indicate that Qur'anic brotherhood fostered trust and bonding social capital; institutions such as the mosque and zakāt system promoted cooperative networks and bridging capital; and Qur'anic injunctions like enjoining good and mutual aid institutionalized reciprocal norms. The study concludes that Qur'anic principles, through practical and historical functions, offered mechanisms for strengthening trust, enhancing cooperation, and reducing inequality. These insights provide applicable lessons for modern social integration policies, institutional development, and community cohesion. The
comparative analysis of verses, tafsīr, and historical practices forms the foundation of the article's practical recommendations.