۞ 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 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 He said: the knowledge is only with Allah, and I preach unto you that wherewith I have been sent, but I see 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 It will destroy everything at the bidding of its Lord." So in the morning there was nothing but their empty dwellings to be seen. That is how We requite the sinners. 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