So when you meet (in the battle) those who do not believe, strike off their necks until when you dominate them, then strengthen the bounds (of imprisonment); then afterwards, either show favour or ransom (them), till the war (ends and) lays down its burdens (do like) that. And if Allah wills, He can defend (you) from them, but (He involves you in such situations) that He may test some of you by means of others. And those who are killed in the way of Allah, their deeds will never be lost.