Al-Anfal 8:17

Falam taqtuloohum walakinna Allahaqatalahum wama ramayta ith ramayta walakinnaAllaha rama waliyubliya almu/mineena minhu balaanhasanan inna Allaha sameeAAun AAaleem

And you did not kill them, but it was Allāh who killed them. And you threw not, [O Muḥammad], when you threw, but it was Allāh who threw that He might test the believers with a good test. Indeed, Allāh is Hearing and Knowing.

So, it is not you who killed them, but in fact Allah killed them. And you did not throw when you threw but Allah did throw, so that He might bless the believers with a good favour. Surely, Allah is All-Hearing, All-Knowing.