This study aimed to refine the formulation of an innovative cash waqf management model designed to address the infrastructural and economic demands of Nusantara, the future capital of Indonesia. Employing a multimethod qualitative research approach, the study integrateds qualitative insights from a comprehensive literature review and a comprehensive qualitative analysis through the grounded theory method, underpinned by principles of Islamic finance and contemporary financial innovation. The findings revealed that the proposed cash waqf model leveraged communal wealth for long-term developmental projects, ensuring sustainability and adherence to Islamic jurisprudence. The study concludes with the establishment of a specialized waqf institution to manage these funds, advocating for transparency and accountability to foster trust and a culture of philanthropy. The proposed model not only holds significant potential for transforming the economic landscape of Indonesia's new capital but also offers a blueprint for integrating Islamic philanthropic principles with modern financial strategies, setting a precedent for similar initiatives globally. The research contributes to create a practical and sustainable financial framework that aligns with Indonesia's cultural context and Islamic generosity traditions, facilitating infrastructure development and economic growth.