Is it permissible for the endower to rent out a portion of a property he endowed, and to pay its rent to the needy, and is the income from the rent considered permissible if the endower is unable to monitor the tenant family?

A waqf (endowment) is not established by mere intention, but rather by a statement or an action that customarily indicates it, such as building a mosque and permitting prayers therein. The waqf can be leased out, and this is handled by the endower (waqif) or the superintendent (nazir). Thus, the endower can lease out the endowed property to those in need and distribute the rent among them, or make the property a residence for them. If the endower leases the property to someone who uses it for a permissible purpose, the rent is lawful. However, if the lessee uses it for disobedience, the sin is solely upon him, and the endower is not obliged to monitor the lessee or spy on him.