۞ 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: "Have you come to turn us away from our aliha (gods)? Then bring us that with which you threaten us, if you are one of the truthful!" 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 saw the (Penalty in the shape of) a cloud traversing the sky, coming to meet their valleys, they said, "This cloud will give us rain!" "Nay, it is the (Calamity) ye were asking to be hastened!- A wind wherein is a Grievous Penalty! 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 And We had established them in that which We have not established you, and We made for them hearing, sight, and hearts, but their hearing, sight, and hearts did not help them a thing, because they disbelieved the signs of Allah. And what they mocked encompassed them. 26