What is the ruling on someone who said to his wife, "By talaq he is coming with me," intending that his colleague had told him so, but then his colleague did not come?

The majority of scholars hold that swearing by divorce results in divorce upon breaking the oath. However, Ibn Taymiyyah is of the view that its ruling is the same as swearing by Allah, if one did not intend to make divorce conditional, and it necessitates an expiation for an oath (kaffarat yamin). Since you swore that your colleague would come with you, intending that he had promised you to come, no divorce falls upon your wife, as the reference point for oaths is the intention of the swearer. We should also point out that swearing by divorce is not permissible, and some scholars have gone as far as to consider it forbidden or disliked.