۞ 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 When they saw the scourge advancing towards their valleys, they said: “This is a cloud that will bring much rain to us.” “By no means; it is what you had sought to hasten -- a wind-storm bearing a grievous 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 And yet, We had established them securely in a manner in which We have never established you, [O people of later times;] and We had endowed them with hearing, and sight, and [knowledgeable] hearts: but neither their hearing, nor their sight, nor their hearts were of the least avail to them, seeing that they went on rejecting God's messages; and [in the end] they were overwhelmed by the very thing which they had been wont to deride. 26