Judicial principles and studies
Rent Modification and Decisive Oath in Lease Contracts — Examination
This study addresses divergent precedents on proving rent modifications in written leases by decisive oath and the need to harmonize case law. It examines the interaction between the Evidence Law and the probative strength of a decisive oath.
Updated: 10 September 2026
Prepared and reviewed by: Ashraf Al-Khawaja
Subject
There are conflicting precedents on whether a rent modification stated in a written lease may be proved by a decisive oath, prompting formation of a general panel to unify the case law on this point.
Summary
Under Article 29 of the Evidence Law, personal testimony may not be used to alter a written contract; however, a decisive oath carries probative weight comparable to written evidence. In the case at hand the defendant did not deny the contract's stated annual rent but asserted that an adjustment was made. Jurisprudence permits directing a decisive oath to establish performance of a debt proven by written evidence where personal testimony is not permitted, as reflected in Decision of Distinction in Rights (2023/1019). Because the decisive oath appeals to the defendant's conscience and can conclusively resolve the disputed fact, the rent modification became established from the date set out in the oath; an appellate court's failure to accept that fact was contrary to law. The court should also clarify from the defendant the amounts shown in his schedule, the claimed period, and how those amounts were calculated when he contests entitlement.
Practical significance
Practically, courts may rely on a decisive oath to establish a rent modification recorded in a written lease, and judges should question the defendant about amounts, periods and calculation methods when entitlement is disputed. This is an educational summary and not a judicial text or legal advice.
Sources and references
Verify the official text and latest amendments before relying on this material professionally.