Muhammad 47:4 فاذا لقيتم الذين كفروا فضرب الرقاب حتى اذا اثخنتموهم فشدوا الوثاق فاما منا بعد واما فداء حتى تضع الحرب اوزارها ذالك ولو يشاء الله لانتصر منهم ولاكن ليبلو بعضكم ببعض والذين قتلوا في سبيل الله فلن يضل اعمالهم ٤

So, when you encounter those who disbelieve, then (aim at) smiting the necks, until when you have broken their strength thoroughly, then tie fast the bond, (by making them captives). Then choose (to release them) either (as) a favour (shown to them,), or (after receiving) ransom,until the war throws down its load of arms. That (is Our command.) If Allah willed, He would have (Himself) subjected them to retribution, but (Allah ordered you to fight,) so that He may test some of you through some others. And those who are killed in Allah’s way, He will never let their deeds go to waste.