۞ And mention the brother of Ad; when he warned his people in the sandy plains,-- and indeed warners came before him and after him-- saying Serve none but Allah; surely I fear for you the punishment of a grievous 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 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 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 It will destroy everything at the bidding of its Lord." So in the morning there was nothing but their empty dwellings to be seen. That is how We requite the sinners. 25 And We had established them in that wherein We have not established you, and We appointed for them hearing, and sight, and hearts; and yet their hearing, their sight and their hearts availed them nothing, since they denied the signs of God, and they were encompassed by that they mocked at. 26