Question: If a man who is completely insane deposits with another man a sum of coins that he begs from people, and the man knows the insane person by the name “ʿAlī Ḥijūrī,” and that his town is Ḥajūr; then the insane person disappeared from our area and more than ten years have passed—what is incumbent upon the custodian in this case? Before his insanity, the insane person loved the custodian and trusted him greatly, and the custodian thinks with near-certainty that if the insane man were to return to his previous state he would pardon the custodian and even ask him to accept his pardon?
Answer: The money in the custodian’s hand is a trust. It appears that the custodian is not obliged to search and inquire as with a stray or found item, nor is he obliged to travel to Ḥajūr. Rather, what is incumbent is that he preserve the money until its owner or his heir appears.
The name “ʿAlī Ḥijūrī” from the town of Ḥajūr is not sufficient to identify him; in that case, searching will yield no benefit. If the custodian fully despairs of identifying him, he gives the money in charity; if he later comes to know him, he guarantees (repays) it to him.
If it be said: The seizure by an insane person of the coins he takes is not a valid seizure; only his guardian may validly receive on his behalf; therefore, the insane person does not own what he took, and it would be property without an owner, which—being such—belongs to public interests.
We reply: It is customary for minors and the insane to be permitted to receive tips and coins, and for their guardians to allow them to dispose of that; this has been the practice of commoners and elites alike. In that case, the receipt by the insane person or the minor is valid, and he owns what he received. If what the insane person or the child receives becomes abundant, the guardian must safeguard it.
If it is asked: When the insane person returns, may the custodian return the deposit to him?
We say: If there is no guardian for the insane person, it is permissible to give him from the deposit what someone like him customarily needs—e.g., the cost of breakfast or lunch, the price of tobacco, the price of qāt—just as guardians do for their charges among the insane. In this case, the custodian stands in place of the guardian in the absence of one, if he is upright, and no formal appointment is required.
Source: Min Thimār al-ʿIlm wa al-Ḥikmah vol.2