Surah Muhammad (Muhammad), Verse 4

فَاِذَا لَقِیْتُمُ الَّذِیْنَ كَفَرُوْا فَضَرْبَ الرِّقَابِ حَتّٰۤی اِذَاۤ اَثْخَنْتُمُوْهُمْ فَشُدُّوا الْوَثَاقَ فَاِمَّا مَنًّا بَعْدُ وَاِمَّا فِدَآءً حَتّٰی تَضَعَ الْحَرْبُ اَوْزَارَهَا ذٰلِكَ وَلَوْ یَشَآءُ اللّٰهُ لَانْتَصَرَ مِنْهُمْ وَلٰكِنْ لِّیَبْلُوَاۡ بَعْضَكُمْ بِبَعْضٍ وَالَّذِیْنَ قُتِلُوْا فِیْ سَبِیْلِ اللّٰهِ فَلَنْ یُّضِلَّ اَعْمَالَهُمْ ۟

Fa-izaa laqeetumul lazeena kafaroo fadarbar riqaabi, hattaaa izaa askhan tumoohum fashuddul wasaaqa, fa immaa mannnam ba'du wa immaa fidaaa'an hattaa tada'al harbu awzaarahaa; zaalika wa law yashaaa'ul laahu lantasara minhum wa laakin li yabluwa ba'dakum bi ba'd; wallazeena qutiloo fee sabeelil laahi falany yudilla a'maalahum

“Therefore, when ye meet the Unbelievers (in fight), smite at their necks; At length, when ye have thoroughly subdued them, bind a bond firmly (on them): thereafter (is the time for) either generosity or ransom: Until the war lays down its burdens. Thus (are ye commanded): but if it had been Allah's Will, He could certainly have exacted retribution from them (Himself); but (He lets you fight) in order to test you, some with others. But those who are slain in the Way of Allah,- He will never let their deeds be lost.”

Quran 47:4 (Yusuf Ali Translation)