What is the ruling on a husband telling his wife: "If you leave without my permission, you are forbidden to me"?

If the husband says to his wife: "If you leave without my permission, then you are forbidden to me," the ruling depends on his intention. If he intended divorce, then a divorce occurs, and he may take her back before the expiration of her iddah (waiting period) if it was not the third divorce. If he intended ẓihār (a statement equating one's wife to an unmarriageable kin), then it is ẓihār, and he must offer the expiation for ẓihār before resuming marital relations with her. If he intended an oath by Allah, or had no specific intention, then he must offer the expiation for an oath.