O YOU who have attained to faith! What is amiss with you that, when you are called upon, "Go forth to war in God's cause," you cling heavily to the earth? Would you content yourselves with [the comforts of] this worldly life in preference to [the good of] the life to come? But the enjoyment of life in this world is but a paltry thing when compared with the life to come! 38 If you march not forth, He will punish you with a painful torment and will replace you by another people, and you cannot harm Him at all, and Allah is Able to do all things. 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 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 there been [a prospect of] immediate gain, and an easy journey, they would certainly have followed thee, [O Prophet:] but the distance was too great for them. And yet, [after your return, O believers,] they will swear by God, "Had we been able to do so, we would certainly have set out with you!" - [and by thus falsely swearing] they will be destroying their own selves: for God knows indeed that they are lying! 42