[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 when Allah revealed to the angels, saying: 'I shall be with you. Give courage to the believers. I shall cast terror into the hearts of the unbelievers. Strike them above the necks, smite their finger tips' 12 For they had opposed God and His Apostle; but whosoever opposes God and his Apostle (should know) that God is severe in retribution. 13 "That [is yours], so taste it." And indeed for the disbelievers is the punishment of the Fire. 14 O believers, when you meet unbelievers on the field of battle, do not turn your backs to them. 15 For any one who turns his back on that day, except to manoeuvre or rally to his side, will bring the wrath of God on himself, and have Hell as abode; and what an evil destination! 16 And you did not kill them, but it was Allah who killed them. And you threw not, [O Muhammad], when you threw, but it was Allah who threw that He might test the believers with a good test. Indeed, Allah is Hearing and Knowing. 17 That [is so], and [also] that Allah will weaken the plot of the disbelievers. 18 If you were seeking a victory, victory has now come to you. If you desist, it will be better for you. If you resume We will return, and even if your forces are numerous, they shall not help you at all. And Allah is with the believers. 19