a man came to my father asking to propose to one of my sisters.
My father agreed to give her to him in marriage. Some time later, the man came and asked my father to conclude the marriage contract. My father told him that he first had to ask my sister's opinion about marrying him. As she refused to marry him, my father persisted in asking her to marry him. Each time he asked for her consent, she would refuse and threaten to set herself on fire if she ever knew that he agreed to conclude the marriage contract. A long time later, the man came again demanding to conclude the marriage, and again she refused and threatened to do the same. The man brought my elder brothers and maternal uncle as intermediaries and again she refused. Upon threatening her to marry him, she would cry and wish she had not been created. She told them that she would accept to marry any other man except this one. She told them that were they to make mincemeat of her, she would still refuse to marry him. Then my elder brother suggested marrying her off to him against her will. He said that he was indebted to that man who helped him marry after his wife's family had turned him down. It is now six years (Part No. 18; Page No. 128) since this happened. My elder brother still insists that she should be married to that man. He threatened not to ever visit my father unless he marries her to him unwillingly. This put my father in an embarrassing situation. He asked me to send you this message. I would like to add that the man who proposed to my sister is an old married man who had another wife ten years ago but divorced her. He also seems to be pious. My father asks whether he should marry his daughter off to that man against her will so that his elder son will be content or if he should turn down the proposal. What is the ruling if this marriage is concluded? Will there be any sin on my elder brother, my father, my sister, and the man who insists on marrying her? Please clarify this issue.
If the reality is as you mentioned, it is forbidden for your father to marry your sister off to that man whom she has refused to marry. It is not permissible for your brother to ask his father to force her to marry him. Your brother has to make Kaffarah (expiation) for breaking his oath. May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.