When you meet the unbelievers, smite their necks, then, when you have made wide slaughter among them, tie fast the bonds; then set them free, either by grace or ransom, till the war lays down its loads. So it shall be; and if God had willed, He would have avenged Himself upon them; but that He may try some of you by means of others. And those who are slain in the way of God, He will not send their works astray.