[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 Your Lord inspired the angels saying, "I am with you. Encourage the believers. I shall cast terror into the hearts of the unbelievers and you will strike their heads and limbs; 12 This because they contended against Allah and His Messenger: If any contend against Allah and His Messenger, Allah is strict in punishment. 13 This-- taste it, and (know) that for the unbelievers is the chastisement of fire. 14 O believers, when you encounter the unbelievers marching to battle, turn not your backs to them. 15 Whoso turns his back that day to them, unless withdrawing to fight again or removing to join another host, he is laden with the burden of God's anger, and his refuge is Gehenna -- an evil homecoming! 16 Wherefore ye slew them not, but Allah slew them, and thou threwest not, when thou threwest, but Allah threw, in order that He might prove the believers with a goodly proving from Him. Verily Allah is Hearing, Knowing. 17 This [was God's purpose] - and also [to show] that God renders vain the artful schemes of those who deny the truth. 18 (O disbelievers) if you ask for a judgement, now has the judgement come unto you and if you cease (to do wrong), it will be better for you, and if you return (to the attack), so shall We return, and your forces will be of no avail to you, however numerous it be, and verily, Allah is with the believers. 19