<![CDATA[This study examines the integration of contemporary Islamic law and local culture through the Teseng agreement practiced within the Bugis–Makassar community. Employing normative legal research, it analyzes the Teseng institution using conceptual and comparative legal approaches. The findings reveal that Teseng represents a compelling example of the organic integration of customary law and Islamic law, in which both legal traditions reinforce rather than contradict one another. This integration did not originate from formal state authority but evolved from the community's collective pursuit of justice, mutual trust, and social harmony, with respected local leaders serving as key mediators between the two normative systems. Core customary values, including siri' and pacce, interact harmoniously with Islamic legal principles such as ʿadl (justice), amānah (trustworthiness), and taʿāwun (mutual cooperation), creating a normative framework that often proves more effective than formal legal sanctions. Despite the pressures of modernization, Teseng continues to develop as a dynamic form of living law while providing a contextually grounded and sustainable model for the development of contemporary Sharīʿah economic law. The study makes a significant theoretical contribution by strengthening the concept of living law within the framework of normative legal pluralism, demonstrating that the relationship between Islamic law and customary law is shaped through an organic, bottom-up process of negotiation rather than a hierarchical legal structure. It further enriches contemporary Islamic legal scholarship by showing that muzāraʿah and mukhābarah can be harmonized with local customary institutions when mediated by shared ethical values such as siri', taʿāwun, and amānah. Practically, the study offers a culturally grounded model of dispute resolution that promotes peaceful and equitable outcomes, while academically contributing to broader debates on legal pluralism by affirming that community-based legal traditions remain adaptive, resilient, and relevant in addressing contemporary legal challenges.]]>
