Does divorce take place if I waive my right to my father's money to help cover the costs of my sister's marriage, after I swore an oath of divorce saying, "My wife is divorced from me if I pay a single penny for my sister's marriage"?

You are permitted not to accept your father's gift and donation, and by doing so, you will not break your oath nor will your wife be divorced. However, if you accept the gift and then return it to your father as an aid for your sister's marriage expenses, you will break your oath, and your wife will be divorced, according to the majority of scholars. Ibn Taymiyyah, however, holds that only an expiation for breaking an oath is required. The opinion of the majority is stronger. Therefore, we advise you not to accept the gift from your father so that you do not break your oath, and by doing so, you will have helped him with your sister's marriage expenses. If the oath is broken and divorce occurs, you may take your wife back before her 'iddah (waiting period) expires, if it is the first or second divorce.