[Remember how it was] when He caused inner calm to enfold you, as an assurance from Him, and sent down upon you water from the skies, so that He might purify you thereby and free you from Satan's unclean whisperings and strengthen your hearts and thus make firm your steps. 11 And the Lord said to the angels: "I am with you; go and strengthen the faithful. I shall fill the hearts of infidels with terror. So smite them on their necks and every joint, (and incapacitate them)," 12 they have opposed God and His Messengers." For those who oppose God and His Messengers, God has prepared a severe retribution. 13 Thus (will it be said): "Taste ye then of the (punishment): for those who resist Allah, is the penalty of the Fire." 14 O believers, when you encounter the unbelievers marching to battle, turn not your backs to them. 15 If any do turn his back to them on such a day - unless it be in a stratagem of war, or to retreat to a troop (of his own)- he draws on himself the wrath of Allah, and his abode is Hell,- an evil refuge (indeed)! 16 You did not slay them, but God slew them; and when thou threwest, it was not thyself that threw, but God threw, and that He might confer on the believers a fair benefit; surely God is All-hearing, All-knowing. 17 This is how God causes the (evil) plans of the unbelievers to fail. 18 If you [disbelievers] seek the victory - the defeat has come to you. And if you desist [from hostilities], it is best for you; but if you return [to war], We will return, and never will you be availed by your [large] company at all, even if it should increase; and [that is] because Allah is with the believers. 19