it was not you but god who slew the pagans. it was not you but god who threw dust at them. he did this as a favorable test for the believers. god is allhearing and allknowing.
فلم تقتلوهم ولكن الله قتلهم وما رميت إذ رميت ولكن الله رمى وليبلي المؤمنين منه بلاء حسنا إن الله سميع عليم