Waqf (وقف), as a subject-matter, is an income-generating property or a functional asset whose usufruct is assigned by the owner in perpetuity to a named group of individuals or the public. Once a property is established as a mortmain or waqf, it becomes non-tradable and inalienable property, i.e., its title cannot be transferred under any circumstances. Furthermore, the subject-matter of waqf (mawqoof) is not supposed to be seized by the state or government in normal situations. It is not permissible to alienate the ownership of the public or beneficiaries in waqf because such waqf properties belong to all the Muslims or to the specified beneficiaries and will continue to be so forever. The named beneficiaries are granted ownership of the usufruct (manfa’ah) of the subject-matter so that they can extract it themselves or transfer to others the right to extract if that is made permissible to do so in the waqf contract or deed. The subject of waqf must belong to the waqif (the waqf dedicator) at the time of assigning and declaring it as such. The waqif must divest himself of the ownership of the subject of waqf from the time dedication or assignment takes effect.

Waqf, as an act, is the permanent dedication of a property by a person professing Muslim faith and of sound mind, for the purposes recognized by shari’a as permissible. The legal incidents attached to a waqf are irrevocability, inalienability, and perpetuity. Waqf should not be contingent on an event or transaction, and should not be deferred or planned to take place at a future date. The object of waqf should be identifiable and indictable with reasonable certainty.

Waqf comes in two main categories: public waqf and private waqf (family waqf).