What is the ruling on someone who swore by divorce not to eat with his colleagues and then did eat, what is the expiation for that, and does it count as one of the three divorces?

If a man swears by divorce that he will not eat from his colleagues' lunch, and then eats, a divorce occurs according to the majority of scholars. He may reconcile with his wife before her waiting period (iddah) ends, provided this divorce does not complete the three divorces. Sheikh Al-Islam Ibn Taymiyyah holds the view that he must offer an expiation for an oath (kaffarat yamin) if he did not intend divorce. The divorce of an angry person occurs if he is aware of what he is saying, and does not occur if he is not aware.