Quran 8:40 — The Spoils of War (Al-Anfal)

If they turn away, then you should know that GOD is your Lord and Master; the best Lord and Master, the best supporter.

[8:39] You shall fight them to ward off oppression, and to practice your religion devoted to GOD alone. If they refrain from aggression, then GOD is fully Seer of everything they do.

[8:41] You should know that if you gain any spoils in war, one-fifth shall go to GOD and the messenger, to be given to the relatives, the orphans, the poor, and the traveling alien. You will do this if you believe in GOD and in what we revealed to our servant on the day of decision, the day the two armies clashed. GOD is Omnipotent.