۞ 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 answered: "Hast thou come to seduce us away from our gods? Bring, then, upon us that [doom] with which thou threaten us, if thou art a man of truth!" 22 Said he: "Knowledge [of when it is to befall you] rests with God alone: I but convey unto you the message with which I have been entrusted; but I see that you are people ignorant [of right and wrong]!" 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 all things by commandment of its Lord. And morning found them so that naught could be seen save their dwellings. Thus do We reward the guilty folk. 25 And We had established them in that wherein We have not established you, and We appointed for them hearing, and sight, and hearts; and yet their hearing, their sight and their hearts availed them nothing, since they denied the signs of God, and they were encompassed by that they mocked at. 26