Is a divorce considered valid if a man tells his wife, "By divorce, someone will enter our home today," when he does not intend the word divorce nor does he mean anyone in particular?

The fatwa is that whoever swears an oath of divorce concerning a matter, and that matter occurs, then the divorce has taken place for his wife. As for the ruling on swearing an oath by divorce, scholars have differed between it being forbidden (haram) and disliked (makruh). Some of them consider it forbidden because it disciplines the one who swears by it, and discipline is not applied to something merely disliked. Some of them consider it disliked, and some forbid it if it is something that holds no sanctity.