Quran 8:67 — The Spoils of War (Al-Anfal)

ما كانَ لِنَبِىٍّ أَن يَكونَ لَهُ أَسرىٰ حَتّىٰ يُثخِنَ فِى الأَرضِ ۚ تُريدونَ عَرَضَ الدُّنيا وَاللَّهُ يُريدُ الءاخِرَةَ ۗ وَاللَّهُ عَزيزٌ حَكيمٌ

No prophet shall acquire captives, unless he participates in the fighting. You people are seeking the materials of this world, while GOD advocates the Hereafter. GOD is Almighty, Most Wise.

[8:66] Now (that many new people have joined you) GOD has made it easier for you, for He knows that you are not as strong as you used to be. Henceforth, a hundred steadfast believers can defeat two hundred, and a thousand of you can defeat two thousand by GOD's leave. GOD is with those who steadfastly persevere.

[8:68] If it were not for a predetermined decree from GOD, you would have suffered, on account of what you took, a terrible retribution.