What is the ruling regarding a man who swore to his wife by irrevocable divorce if she went with her sister for treatment in Cairo, and she disobeyed and went, and he does not remember his intention at the time of the oath?

The majority of scholars hold that whoever swears by divorce as a conditional oath or with the intention of threatening, and the condition is met, then he has broken his oath and his wife is divorced. This is the fatwa we adopt. Divorce occurs by the wife going with her sister, and the statement "divorced without return" effects a single revocable divorce according to most scholars. The wife can be taken back if she has not been divorced more than once, and before the 'iddah expires.