۞ 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 He said, “Its knowledge is only with Allah; and I convey to you the messages of my Lord, but I perceive that you are an ignorant nation.” 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 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