۞ And make mention (O Muhammad) of the brother of A'ad when he warned his folk among the wind-curved sandhills - and verily warners came and went before and after him - saying: Serve none but Allah. Lo! I fear for you the doom of a tremendous Day. 21 They said: Hast come to turn us away from our gods? Then bring upon us that wherewith thou threatenest us, if thou art of the truthful. 22 He said, 'Knowledge is only with God, and I deliver to you the Message with which I was sent; but I see you are an ignorant people.' 23 So when they saw it as a cloud advancing towards their valleys, they said: "This is just a passing cloud that will bring us rain." "No. It is what you were trying to hasten: The wind which carries the grievous punishment! 24 Destroying everything by the command of its Lord, so they became such that naught could be seen except their dwellings. Thus do We reward the guilty people. 25 We had strengthened them as We have not strengthened you, had given them ears and eyes and hearts; but nothing stood them in good stead, neither their ears nor eyes nor hearts, for they rejected the signs of God, and were seized by what they had mocked. 26