۞ 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 come to turn us away from our gods? Then bring upon us that wherewith thou threatenest us, if thou art 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 saw it as a sudden cloud coming towards their valleys, they said, 'This is a cloud, that shall give us rain!' 'Not so; rather it is that you sought to hasten -- a wind, wherein is a painful chastisement, 24 bound to destroy everything at its Sustainer's behest!" And then they were so utterly wiped out that nothing could be seen save their [empty] dwellings: thus do We requite people lost in sin. 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