۞ 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 '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 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 And when they saw it as a cloud approaching their valleys, they said, "This is a cloud bringing us rain!" Rather, it is that for which you were impatient: a wind, within it a painful punishment, 24 which will destroy everything at its Lord's behest!" And in the morning there was nothing left to be seen save their [empty] dwellings: thus We repay the evil-doers. 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