۞ And remember the brother of Ad, when he warned his people beside the sand-dunes -- and already warners had passed away alike before him and behind him -- saying, 'Serve none but God! Truly I fear for you the chastisement of a dreadful day. 21 They said: "Hast thou come in order to turn us aside from our gods? Then bring upon us the (calamity) with which thou dost threaten us, if thou art telling the truth?" 22 He said: "The knowledge (of the time of its coming) is with Allah only, and I convey to you that wherewith I have been sent, but I see that you are a people given to ignorance!" 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 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 We had established them firmly in a manner We have not established you. We had given them ears and eyes and hearts. But nothing availed them -- neither their ears, nor their eyes, nor their hearts, for they denied the Signs of Allah. Then what they had mocked at encompassed them. 26