He—may Allah have mercy on him—was asked:

A man appointed another man as his agent to manage his land grant at Bayt. The agent leased out its land at a fair rate according to local custom, seeking his principal’s benefit and best interests. The cultivators, however, conspired to deceive the agent, since he was a stranger to the district and lacked experience and knowledge of its conditions and characteristics. They obtained leases from him at less than the customary fair rate received by the other grant-holders in the district, whose lands were on an equal footing, without any great disparity or gross inequity. May the grant-holder demand rent from the cultivators at the fair rate, on the same basis as his fellow grant-holders in the district?

He replied:

If he appointed him to lease it out under an unrestricted agency, or told him, “Lease it out on the same terms as comparable land,” the ruling is the same whether the agency was unrestricted or expressly qualified in this way: the agent may lease it out only at the fair rental value applicable to comparable land. If the agent was negligent, leasing it for less than the customary rent and handing the land over to the tenant, the principal may demand that the agent make up the shortfall.

If the person taking the lease told the agent, “This rent is in line with what others pay,” but it subsequently became clear