Is it permissible to annul a three-year land lease contract due to an increase in the annual rent beyond what was agreed upon, knowing that the current rent is less than the market price, or is the contract the law between the contracting parties?

An agent authorized to sell or lease is not permitted to transact for less than the market price or market rent, as this is considered a deviation from the customary limits of agency. Custom dictates that an absolute agent acts in a manner that serves the best interest and benefit of his principal.

If the agent sells or leases for less than the market price or market rent, with a significant disparity (ghabn fāḥish), this transaction is not valid according to the majority of jurists, including Al-Shafi'i and Ahmad in one of their two opinions. In such a case, the principal has the option to either uphold the contract or annul it, and he may also hold the negligent agent liable for the difference between the transacted price/rent and the market price/rent.