What is the ruling on a son's actions of not communicating with his mother, and is this considered an act of disobedience (ʿUqūq)? And what is the ruling on a father refusing to speak with his son and withholding his allowance due to smoking and the son's handling of his own money? And what is the ruling on a father considering expelling his son and the son considering leaving home?

Your friend must fear Allah concerning his parents, for what he did to his mother and father is not permissible for him. His mother has great rights over him, and he must communicate with her and visit her. He must obey his father in what is good, especially if his father orders him to quit smoking, which is forbidden by Islamic law. If the father's prohibition of smoking combines with the religious prohibition of smoking, the son would be sinful in two ways: for smoking and for not obeying his father's command. Everyone is advised to be patient and understanding, and the father should not expel his son lest he expose him to something worse. As for you, the questioner, you must advise them and remind them of Allah.