What is the ruling of Islamic law on one who frequently, and unwillingly, considers swearing by divorce, and is assailed by doubt as to whether it is a mere thought or actual utterance? Does divorce occur without his knowledge? And how can he get rid of these obsessive thoughts?

We advise you to be patient with this trial and to supplicate Allah Almighty frequently to remove it from you. You should also perform ruqyah (Islamic exorcism). As for these doubts you are experiencing concerning the divorce of your wife, do not pay any attention to them, nor do they hold any weight, because the marital bond is firmly established with certainty and is not removed by doubt regarding divorce.