[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 [Remember] when your Lord inspired to the angels, "I am with you, so strengthen those who have believed. I will cast terror into the hearts of those who disbelieved, so strike [them] upon the necks and strike from them every fingertip." 12 This because they contended against Allah and His Messenger: If any contend against Allah and His Messenger, Allah is strict in punishment. 13 That is your punishment, taste it then; and know that for those who deny the truth there is the punishment of the Fire. 14 O Ye who believe! whenever ye meet those who disbelieve marching slowly turn to them not your backs. 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 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 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