The transmission of Vedic knowledge across civilizations has depended not only on sacred texts but also on the linguistic systems through which religious knowledge is preserved, interpreted, and transmitted. Within the Hindu intellectual tradition of Nusantara, the coexistence of Sanskrit and Kawi in palm-leaf manuscripts represents a distinctive bilingual tradition that has sustained the continuity of Vedic thought. However, existing scholarship has primarily examined Lontar Ganapati Tattwa from philological, theological, or cosmological perspectives, while its Sanskrit–Kawi bilingual structure as an epistemological mechanism remains insufficiently explored. This study investigates how the Sanskrit–Kawi linguistic system functions as a medium for transmitting Vedic epistemology in Nusantara from the perspective of the philosophy of language. Employing a qualitative library-based approach, the study integrates philological analysis, philosophical hermeneutics, and qualitative content analysis. The primary source is the Lontar Ganapati Tattwa manuscript, supported by scholarly works on Sanskrit, Hindu philosophy, manuscript studies, and the philosophy of language. The findings demonstrate that Sanskrit and Kawi operate as complementary epistemological systems: Sanskrit preserves the canonical authority of Vedic teachings, while Kawi contextualizes and interprets them within the cultural horizon of Nusantara. Furthermore, Vedic knowledge is transmitted through interconnected processes of preservation, hermeneutic interpretation, cultural internalization, and intergenerational regeneration, illustrating that vernacularization involves epistemic reinterpretation rather than mere translation. The study proposes the Sanskrit–Kawi Epistemic Transmission Model, offering a new conceptual framework for understanding the transmission of religious knowledge and providing practical implications for Hindu manuscript preservation, Sanskrit–Kawi studies, Hindu education, and the revitalization of Nusantara intellectual heritage.