Swearing that his wife will be unlawful for him if he is not telling the truth and discovering that it is not the truth

Q: I am a student who was sent to study outside the Kingdom of Saudi Arabia, and I am married. One day, during a discussion between me and my colleague, I mentioned something to him, but he did not believe me. Even when I swore to him by Allah, he did not believe me. So I became angry and said, “My wife will be Haram (forbidden) for me if I am not telling the truth,” so he would be convinced. (Part No. 20; Page No. 88) I also said some other things that I cannot remember now. However, after thinking the matter over I realized that I had not told the truth. I asked some people about this, but I have not found a Fatwa (legal opinion issued by a qualified Muslim scholar) that will set my heart at rest. My wife at present is in Saudi Arabia and she is pregnant.

A: Your wife is not divorced, as long as when you made the oath, declaring her to be Haram for you, you thought that you were telling the truth, even though in reality you were not. However, if you knew at the time of oath-making and forbidding that you were telling a lie, you must make Kaffarah (expiation) for your broken oath. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, and his family and his Companions.