it was not you who killed them but god did so. you did not throw what you threw but god to bring out the best in the faithful by doing them a favour of his own. 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