Section
Waqf is a binding contract that cannot be undone1 through rescission or by any other means. It may neither be gifted, pledged, inherited, nor sold—unless its benefit has ceased because of ruin or the like and no means of repair can be found. In that situation it may be sold, and the price must be spent on an equivalent2 or on something partially equivalent; the very moment the substitute3 is purchased it becomes waqf.

The same ruling applies to a mosque that has become too small for its congregation, whose neighborhood has fallen into ruin, or whose location has become repugnant. The fixtures and stones of such a mosque may be transferred to another mosque that needs them, and that is preferable to selling them. It is also permissible to dismantle the mosque’s minaret and incorporate it into one of its walls for reinforcement.

If an endowment is made for a frontier post and that post ceases to function, the benefit is redirected to another frontier of the same kind; by analogy, the same applies to mosques, ribats, and the like.

It is forbidden to dig wells or plant trees in mosques4 —and this, it seems, applies only where no5 benefit is involved.