A Waqf property is indeed a property of Allah used to service and benefit mankind. Therefore such property is bounded by Islamic law and should remain the property of Muslims forever. Thus this criterion originally prevents the said asset from being inherited, sold or exchanged except in certain situations and that is where the concept of Istibdal comes in.
The concept of Istibdal is one used in discussions of Waqf properties. Istibdal is an Arabic word derived from the word “Badal” which means to change or replace. In true essence, Istibdal means to sell what is lacking or a waqf property that has lost its revenue to buy what is better than that.
The Istibdal law sees to the conversion of a type of waqf into another type and this is usually the case in the conversion of cash Waqf into real estate Waqf. Furthermore, the implementation of this concept is in three procedures. First is the initial acquisition of a Waqf asset, then comes the identification of unproductive Waqf asset and last would be the opening of Istibdal suggestions from individuals, agencies or developers for Waqf development.
Similarly, with regard to its execution, there are variations amongst Islamic scholars. The Hanafi school believes that Istibdal must be implemented to solve any problems that may affect a waqf property. This should still be the case even if the waqf property is still in good condition but the implementation of Istibdal would see to more benefits and better results. However, in the Maliki school of thoughts, the scholars are of the opinion that implementation should defer between movable and immovable waqf property. They agree that it is necessary to perform Istibdal on movable properties as they are more vulnerable to damage whereas, in the case of an immovable asset, implementation of Istibadal should only be when the property is in an emergency and can only be substituted with a similar property.
Meanwhile, scholars from other schools of thoughts like the Shafii have permitted a limited scope for the execution of Istibdal. They believe that a Waqf property is a property of Allah and thus cannot be changed in any way. This view of theirs is backed by the incidence where Saidina Umar R.A stated that a Waqf property cannot be sold, hired and inherited. Much like the Hanafi school, scholars of the Hanbali school also permit for the implementation of Istibdal both on movable and immovable properties however only when they are damaged.