When He caused calm to fall on you as a security from Him and sent down upon you water from the cloud that He might thereby purify you, and take away from you the uncleanness of the Shaitan, and that He might fortify your hearts and steady (your) footsteps thereby. 11 And the Lord said to the angels: "I am with you; go and strengthen the faithful. I shall fill the hearts of infidels with terror. So smite them on their necks and every joint, (and incapacitate them)," 12 they have opposed God and His Messengers." For those who oppose God and His Messengers, God has prepared a severe retribution. 13 "That [is yours], so taste it." And indeed for the disbelievers is the punishment of the 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 Ye (Muslims) slew them not, but Allah slew them. And thou (Muhammad) threwest not when thou didst throw, but Allah threw, that He might test the believers by a fair test from Him. Lo! Allah is Hearer, Knower. 17 This is how God causes the (evil) plans of the unbelievers to fail. 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