When He made the slumber fall upon you as a reassurance from him and sent down water from the sky upon you, that thereby He might purify you, and remove from you the fear of Satan, and make strong your hearts and firm (your) feet thereby. 11 Lo! Thy Sustainer inspired the angels [to convey this His message to the believers]: "I am with you!" [And He commanded the angels:] "And give firmness unto those who have attained to faith [with these words from Me]: 'I shall cast terror into the hearts of those who are bent on denying the truth; strike, then, their necks, [O believers,] and strike off every one of their finger-tips!" 12 That is because they opposed Allah and His messenger. Whoso opposeth Allah and His messenger, (for him) lo! Allah is severe in punishment. 13 This-- taste it, and (know) that for the unbelievers is the chastisement of fire. 14 Believers, whenever you encounter a hostile force of unbelievers, do not turn your backs to them in flight. 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 It was not you (believers) but God who slew the pagans. It was not you (Muhammad) but God who threw dust at them. He did this as a favorable test for the believers. God is All-hearing and All-knowing. 17 This is how God causes the (evil) plans of the unbelievers to fail. 18 (Tell the unbelievers:) 'If you have sought a judgement, then surely a judgement has come to you. And if you desist from disobedience, it is all the better for you. But if you revert to your mischief, We will again chastise you; and your host, howsoever numerous, will never be of any avail to you. Know well, Allah is with the believers.' 19