Kuwait Court of Cassation principle number 953

Exercise of the right of retention is subject to the established rule in transactions that the exercise of rights is restricted so as to prevent arbitrariness and abuse. Its effect. A person invoking his right to retain what is in his possession until he obtains his entitlement from his debtor may not exercise that right in a manner inconsistent with the requirements of good faith and integrity in dealings. A person to whom possession of a thing has passed through an unlawful act may not retain it until he recovers from its owner the expenses of preserving it during the period it remained with him. He must deliver it to the owner immediately and then seek recovery of those expenses from him. - The judgment's ordering simultaneous performance of delivery and restitution between the parties on the basis that each may retain what is in his possession until he obtains his entitlement from the other, although possession of the thing delivered to him was acquired under a void contract contrary to public order, is a violation of the law.