۞ 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: art thou come unto us that thou mayest turn us aside from our gods? then bring thou upon us that wherewith thou threatenest us, if thou art of the truth-tellers. 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 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 And verily We had empowered them with that wherewith We have not empowered you, and had assigned them ears and eyes and hearts; but their ears and eyes and hearts availed them naught since they denied the revelations of Allah; and what they used to mock befell them. 26