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 you go not forth, He will chastise you with a painful chastisement, and instead of you He will substitute another people; and you will not hurt Him anything, for God is powerful over everything. 39 If you do not support him [Muhammad], know that God did support him when those who denied the truth expelled him when the two of them were in the cave, he [Muhammad] told his companion, "Do not worry; for God is with us." So God sent His tranquillity down on him and aided him with forces invisible to you and placed the word of those who disbelieved lowest, while God's word remained supreme. God is powerful and wise. 40 O believers, go out in the cause of God, (whether) light or heavy, and strive in the service of God, wealth and soul. This is better for you if you understand. 41 Were it a gain near at hand, and an easy journey, they would have followed thee; but the distance was too far for them. Still they will swear by God, 'Had we been able, we would have gone out with you,' so destroying their souls; and God knows that they are truly liars. 42