۞ 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 thou come in order to turn us aside from our gods? Then bring upon us the (calamity) with which thou dost threaten us, if thou art telling the truth?" 22 Said he: "Knowledge [of when it is to befall you] rests with God alone: I but convey unto you the message with which I have been entrusted; but I see that you are people ignorant [of right and wrong]!" 23 Then, when they saw it as a dense cloud coming towards their valleys, they said: "This is a cloud bringing us rain!" Nay, but it is that (torment) which you were asking to be hastened! a wind wherein is a painful torment! 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 We had indeed given them the means which We have not given you, and made ears and eyes and hearts for them; so their ears and eyes and hearts did not benefit them at all because they used to deny the signs of Allah, and the punishment they used to mock at encompassed them. 26