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 when Allah revealed to the angels, saying: 'I shall be with you. Give courage to the believers. I shall cast terror into the hearts of the unbelievers. Strike them above the necks, smite their finger tips' 12 This because they contended against Allah and His Messenger: If any contend against Allah and His Messenger, Allah is strict in punishment. 13 Thus (will it be said): "Taste ye then of the (punishment): for those who resist Allah, is the penalty of the Fire." 14 O believers, when you encounter the unbelievers marching to battle, turn not your backs to them. 15 Whoso on that day turneth his back to them, unless manoeuvring for battle or intent to join a company, he truly hath incurred wrath from Allah, and his habitation will be hell, a hapless journey's end. 16 So the fact is that it was not you, but it was Allah Who killed them; and it was not you when you threw [sand at them], but it was Allah Who threw it, (and the believers were employed for the task) that He might cause the believers to successfully pass through this test. Allah is All-Hearing, All-Knowing. 17 Therefore take this, and (know that) Allah will weaken the scheme of the disbelievers. 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