What is the ruling on bequeathing the donation of one's organs after death?

The Shaykh : That is an unjust bequest that cannot be carried out. When a person dies, he moves from this world to the barzakh (the interval between death and resurrection); so he has no right to dispose of his body after his death as if he were still alive. Add to this that it involves mutilation, and mutilation is prohibited even with regard to disbelievers. The Prophet (peace and blessings be upon him) used to forbid the Companions from mutilating the bodies of disbelievers who were killed, so it is even more so and more necessary that this be avoided if the donor is a Muslim, even after his death.