What is the ruling on someone who swore not to return to a certain act, and that if he did return to it, he would give a large sum of money in charity that he cannot afford, then he returned to the same act?

The wording encompassed two matters: a binding oath and a vow of obstinacy and anger. Both necessitate an expiation for an oath (kaffarat yamin) upon breaking them. Therefore, two expiations for an oath are incumbent upon you. The expiation for an oath is the freeing of a slave, or feeding ten poor people, or clothing them. If you cannot find any of these, then fasting for three days. It is advisable to avoid such an action if it is forbidden, and not to be hasty in swearing oaths.