Quran 8:16 — The Spoils of War (Al-Anfal)

Anyone who turns back on that day, except to carry out a battle plan, or to join his group, has incurred wrath from GOD, and his abode is Hell; what a miserable destiny!

[8:15] O you who believe, if you encounter the disbelievers who have mobilized against you, do not turn back and flee.

[8:17] It was not you who killed them; GOD is the One who killed them. It was not you who threw when you threw; GOD is the One who threw. But He thus gives the believers a chance to earn a lot of credit. GOD is Hearer, Omniscient.