What is the ruling on someone who swore not to borrow money from his brother by saying, "By God, I will not borrow from him," or "It is Haram for me if I borrow from him," and then doubted the wording of his oath?

If you have not broken your oath, then there is nothing upon you. However, if you have broken it, then expiate for your oath and resume your dealings with your brother, due to the resulting harmony and love. And breaking the oath is preferable in this case, for the Prophet, peace and blessings be upon him, said: "Whoever takes an oath and then sees something better than it, let him do what is better and expiate for his oath."