So when you confront the disbelievers , strike at their necks ; until when you have slain them in plenty , tie them up firmly ; then after that , you may either release them as a favour or take ransom , until the war lays down its ordeal ; this is it ; and had Allah willed He Himself could have taken revenge from them , but this is to test some of you with others ; and Allah will surely never waste the deeds of those who were killed in His way .