۞ 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 delude us away from our gods? Then bring us what you promise us, if you should be of the truthful." 22 He said: "The Knowledge (of when it will come) is only with Allah: I proclaim to you the mission on which I have been sent: But I see that ye are a people in 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 shall annihilate everything by the command of its Lord. Wherefore they became such that naught could be seen save their dwellings Thus We requite a nation of the culprits. 25 And assuredly We had established them in that flourishing condition wherein We have not established you, and We had appointed for them hearing and sight and hearts; yet their hearing and sight and heart availed them not at all, they became wont to gainsay the revelations of Allah, and surrounded them that whereat they had been mocking. 26