[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 When your Lord revealed to the angels: I am with you, therefore make firm those who believe. I will cast terror into the hearts of those who disbelieve. Therefore strike off their heads and strike off every fingertip of them. 12 That was because they defied God and His Messenger. He who defies God and His Messenger shall be severely punished by God. 13 That is your punishment (from Allah). So taste this punishment, and know that for the unbelievers is the punishment of the Fire. 14 Believers, whenever you encounter a hostile force of unbelievers, do not turn your backs to them in flight. 15 And whoever turns his back to them on such a day - unless it be a stratagem of war, or to retreat to a troop (of his own), - he indeed has drawn upon himself wrath from Allah. And his abode is Hell, and worst indeed is that destination! 16 And yet, [O believers,] it was not you who slew the enemy, but it was God who slew them; and it was not thou who cast [terror into them, O Prophet,] when thou didst cast it, but it was God who cast it: and [He did all this] in order that He might test the believers by a goodly test of His Own ordaining. Verily, God is all-hearing, all-knowing! 17 That was that, but remember God will make the plots of the unbelievers contemptible. 18 If you demanded a judgment, the judgment has then indeed come to you; and if you desist, it will be better for you; and if you turn back (to fight), We (too) shall turn back, and your forces shall avail you nothing, though they may be many, and (know) that Allah is with the believers. 19