Lady Zaynab’s (sa) sermon in Kufa is among the most significant post-Ashura texts, functioning as a critical discourse confronting the social apathy of its time. This study addresses the following questions: Within what discursive framework, and through which key signifiers, is social responsibility represented in Lady Zaynab’s (sa) Kufan sermon? Moreover, how is the discursive antagonism of the sermon constructed through the opposition between social responsibility, on the one hand, and social indifference, on the other? Employing the discourse-analytical framework of Laclau and Mouffe, this research examines the sermon as a discursive text and demonstrates that it operates beyond a mere historical event; rather, it constitutes an active semantic system contributing to identity formation, discursive boundary-making, and the revitalization of social responsibility within the Shiʿi community. By exposing the mechanisms of injustice and worldliness, the sermon establishes a decisive othering between the community of truth and the community of falsehood, presenting social indifference as an excluded element aligned with the discourse of oppression. Conversely, social responsibility is foregrounded as a necessary condition for the formation and continuity of the Ahl al-Bayt’s (as) discursive community.The article argues that Lady Zaynab’s (sa) sermon in Kufa—through the discursive mechanism of foregrounding social responsibility and legitimizing it via its linkage to religious values—constructs a counter-hegemony against the Umayyad discourse. Consequently, the study shows that the sermon, far from being merely a historical or emotive text, possesses a discursive and hegemonic capacity that remains instructive for analyzing the necessity of social responsibility in contemporary societies.