Does a divorce take place if the husband says to his wife: "My mother would have committed adultery with me if I do not divorce you"?

The statement made by the husband does not constitute a divorce; it is merely a promise and a threat, and divorce does not occur solely by them. However, this statement is a reprehensible and ugly utterance that is not permissible to articulate. The husband must repent to Allah for it by ceasing to utter it, feeling remorse, and resolving never to repeat it.