The Quran

يا أَيُّهَا النَّبِيُّ قُل لِمَن في أَيديكُم مِنَ الأَسرىٰ إِن يَعلَمِ اللَّهُ في قُلوبِكُم خَيرًا يُؤتِكُم خَيرًا مِمّا أُخِذَ مِنكُم وَيَغفِر لَكُم ۗ وَاللَّهُ غَفورٌ رَحيمٌ

Muhammad Asad

[Hence,] O Prophet, say unto the captives who are in your hands: "If God finds any good in your hearts, He will give you something better than all that has been taken from you, and will forgive you your sins: for God is much-forgiving, a dispenser of grace."¹

I.e., "If God finds in your hearts a disposition to realize the truth of His message, He will bestow on you faith and, thus, the good of the life to come: and this will outweigh by far your defeat in war and the loss of so many of your friends and companions." Although these words relate primarily to the pagan Quraysh taken prisoner in the battle of Badr, they circumscribe the Islamic attitude towards all unbelieving enemies who might fall into the believers' hands in the course of war. For a further discussion of the problem of prisoners of war, see 47:4.