The elucidation of the divine status of the Ahl al-Bayt and the consolidation of the principle of Imamate within the religious and social sphere after ʿAshura constituted one of the most fundamental missions of Imam al-Sajjad in confronting the dominance of Umayyad discourse. In a context in which the prevailing political order had constrained any overt defense of the authority of the Ahl al-Bayt, and in which the official reading of religion had been organized so as to marginalize their sacred authority, the Imam, through the language of supplication, developed a mode of indirect yet profoundly effective engagement for articulating the theology of Imamate. Employing a descriptive-analytical method and grounded in a text-centered analysis of al-Sahifa al-Sajjadiyya, the present study seeks to answer the question of how Imam al-Sajjad made use of the theological capacity of supplication to expound the status of the Ahl al-Bayt and to consolidate their religious and spiritual authority. The findings show that, within Imam al-Sajjad’s intellectual framework, supplication is not merely a devotional and individual form of expression, but rather a theological, pedagogical, and identity-forming mechanism through which the foundational elements of Imamate are reproduced and internalized within the religious consciousness of the community. Accordingly, at the explicative level, the Imam, by rearticulating such concepts as guidance, authoritative proof, purity, divine election, and mediation of grace, presents the Ahl al-Bayt as the legitimate channels of religious knowledge and the true interpreters of revelation; and at the teleological level, by delineating the cognitive, existential, and social effects of Imamate, he portrays it as indispensable for the preservation of religion, the cohesion of the community, and the attainment of worldly and otherworldly felicity