Is a divorce effected or is an expiation incumbent upon one who said to his wife: "Divorce on me if I drive the car," and then he drove the car, knowing that his only intention was not to drive it?

The statement "I divorce you if I drive the car" is a conditional divorce (talaq mu'allaq). The majority of jurists hold that the divorce takes effect upon the fulfillment of the condition. However, some scholars, such as Ibn Taymiyyah, believe that the matter depends on the husband's intention: if he intended divorce, it occurs; but if he intended prohibition (to prevent himself from doing something), then he must offer expiation for an oath (kaffarat yamin) if he breaks his vow. Therefore, if you did not intend divorce but rather prevention, then you must offer expiation for an oath if you drive the car. Caution should be exercised when using divorce pronouncements.