What is the legal ruling regarding a husband's utterance to his wife, "You are unlawful to me if I approach you," without intention or purpose and in a state of extreme anger?

The reality of what happened with the husband is his suspending the prohibition of his wife on his intercourse with her. In this matter, since the husband did not intend anything by his prohibition, the preponderant opinion is that he is obligated to offer an expiation for an oath (kaffarat yamin). As for his uttering that during a moment of anger, there is a detailed explanation for it.