What is the ruling regarding a husband's statement: "My wife is unlawful to me if my brother comes into our house," and then the brother enters the house a year later? And what is its expiation?

Scholars have differed concerning the ruling on swearing to prohibit one's wife. The fatwa adopted by us is that if the husband intended divorce, a single repudiation occurs, and he may take his wife back before the expiry of her 'iddah, provided this repudiation does not complete the three. If he intended ẓihār, then ẓihār occurs, and the expiation mentioned in Surat Al-Mujadilah becomes obligatory upon him. If he intended an oath, or did not intend anything specific, then an expiation for an oath is due upon him. It must be noted that swearing by al-haram (the forbidden) is impermissible; the permissible oath is to swear by Allah the Almighty.