“I once asked abu al-Hassan (a.s.), about the case of a man who makes a piece of his property an endowment, then decides to change it. He (the Imam) said, ‘If he has made it an endowment for his children and others and then appoints a supervisor for it, he cannot change it. If they are small and he has set a condition that the supervision will rest with them until they mature and so he has taken possession for them in this case also he cannot change it. If they are mature but he has not given it to them and they do not dispute with him until they take possession from him, then he can change it because they have not taken possession from him while they are mature.’”