Quran 8:56 — The Spoils of War (Al-Anfal)

You reach agreements with them, but they violate their agreements every time; they are not righteous.

[8:55] The worst creatures in the sight of GOD are those who disbelieved; they cannot believe.

[8:57] Therefore, if you encounter them in war, you shall set them up as a deterrent example for those who come after them, that they may take heed.