Al-Anfal - 8:17

فَلَمْ تَقْتُلُوهُمْ وَلَـكِنَّ اللّهَ قَتَلَهُمْ وَمَا رَمَيْتَ إِذْ رَمَيْتَ وَلَـكِنَّ اللّهَ رَمَى وَلِيُبْلِيَ الْمُؤْمِنِينَ مِنْهُ بَلاء حَسَناً إِنَّ اللّهَ سَمِيعٌ عَلِيمٌ
[8:17]
So you did not slay them, but it was Allah Who slew them, and you did not smite when you smote (the enemy), but it was Allah Who smote, and that He might confer upon the believers a good gift from Himself; surely Allah is Hearing, Knowing.
It is not ye who slew them; it was Allah: when thou threwest (a handful of dust), it was not thy act, but Allah's: in order that He might test the Believers by a gracious trial from Himself: for Allah is He Who heareth and knoweth (all things).
Ye (Muslims) slew them not, but Allah slew them. And thou (Muhammad) threwest not when thou didst throw, but Allah threw, that He might test the believers by a fair test from Him. Lo! Allah is Hearer, Knower.