What is the ruling of Islamic law regarding a husband who swore an oath upon his wife that she must eat a certain food that she dislikes, and she was unable to finish it, knowing that her previous lack of eating had caused a miscarriage?

It is disliked to embarrass one's wife by swearing an oath to compel her to do something she dislikes. If the one who swore the oath did not intend to oblige her to eat all the food, or if his intention was to honor her, then there is no breaking of the oath. However, if he intended to oblige her to eat all the food and she did not do so, then an expiation for the oath is incumbent upon him: feeding ten poor persons, or clothing them, or freeing a slave. If he is unable to do so, then fasting three days.