Prophet Muhammad PBUH says, “When a person dies, his/her acts come to an end, but three: Sadaqah Jariyah (recurring or ongoing charity), useful/beneficial knowledge, or a pious child who prays for the deceased.” (Sunan Ibn Mājah 237)
Waqf falls into the first category; Sadaqah Jariyah, which means that it continues to benefit the donor in the long-term and continues to earn the donor rewards even after death. It generates rewards from Allah SWT for as long as the asset is beneficial for public use. Waqf was defined as an exclusive form of giving, of a non-movable asset from the owner. Today, Waqf can also be defined as a monetary waqf which is to be used towards the purchase or construction of a non-movable asset. The non-movable asset would then be beneficial for public use.