۞ And mention the brother of Ad; when he warned his people in the sandy plains,-- and indeed warners came before him and after him-- saying Serve none but Allah; surely I fear for you the punishment of a grievous day. 21 'Have you come to turn us away from our gods (they replied)? If what you say is true then bring down that which you promise us' 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 Then, when they beheld it as a dense cloud coming toward their valleys, they said: Here is a cloud bringing us rain. Nay, but it is that which ye did seek to hasten, a wind wherein is painful torment, 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 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