Waqf (plural: Awqaf) is a charitable endowment in Islamic law, representing a permanent dedication of property or assets for religious, charitable, or philanthropic purposes. Once an asset is declared Waqf, it is irrevocably dedicated to Allah, cannot be sold, inherited, or gifted, and its proceeds must be used exclusively for the designated charitable purpose. The practice is rooted in the Sunnah of Prophet Muhammad (peace be upon him), who encouraged endowment and himself established Waqf properties. When Umar ibn al-Khattab acquired land in Khaybar and asked how to use it optimally, the Prophet advised: "If you wish, make the property itself inalienable and give its proceeds in charity" (Bukhari and Muslim). Throughout Islamic history, Awqaf have funded mosques, schools, universities, hospitals, libraries, water systems, orphanages, and public infrastructure, forming the backbone of civil society. The famous Al-Azhar University in Cairo and many Ottoman charitable institutions were sustained by Waqf endowments. Waqf represents a unique fusion of religious devotion and social welfare, allowing Muslims to earn ongoing rewards (Sadaqah Jariyah) even after death while building sustainable institutions serving communities across generations. Modern applications include cash waqf, corporate waqf, and waqf shares. The waqf system has been called one of the most sophisticated social welfare mechanisms in history. It allowed individuals to designate their wealth for perpetual public benefit while ensuring professional management. Waqf endowments funded the golden age of Islamic civilization,from the great libraries of Baghdad and Cordoba to the hospitals of Cairo and Damascus. The concept has seen renewed interest in contemporary Islamic finance as a tool for social development, poverty alleviation, and sustainable community projects. Waqf exemplifies Islam's vision of wealth as a trust (amanah) to be used for the common good, not merely personal consumption. It transforms private wealth into public benefit that continues rewarding the donor long after their death. The revival of waqf in modern contexts offers Muslims a powerful tool for addressing social needs while earning eternal reward.