the believing men and women must not feel free to do something in their affairs other than that which has been already decided for them by god and his messenger. one who disobeys god and his messenger is in plain error.
وما كان لمؤمن ولا مؤمنة إذا قضى الله ورسوله أمرا أن يكون لهم الخيرة من أمرهم ومن يعص الله ورسوله فقد ضل ضلالا مبينا