O you who believe! What (excuse) have you that when it is said to you: Go forth in Allah's way, you should incline heavily to earth; are you contented with this world's life instead of the hereafter? But the provision of this world's life compared with the hereafter is but little. 38 If ye march not forth, He will torment you with a torment afflictive, and will substitute for you a people - other than you; and Him ye cannot hurt in aught; and Allah is over everything Potent. 39 If you will not aid him, Allah certainly aided him when those who disbelieved expelled him, he being the second of the two, when they were both in the cave, when he said to his companion: Grieve not, surely Allah is with us. So Allah sent down His tranquillity upon him and strengthened him with hosts which you did not see, and made lowest the word of those who disbelieved; and the word of Allah, that is the highest; and Allah is Mighty, Wise. 40 March forth light and heavy and strive hard with your riches and your lives in the way of Allah; that is the best for you, if ye have knowledge. 41 Had the gain been immediate and the journey shorter, they would have followed you: but the distance seemed too great for them. Yet they will swear by God, "Had we been able, we would have gone out with you." They bring ruin upon themselves. God knows that they are surely lying. 42