۞ 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: “Have you come to us to turn us away from our gods? Then, bring upon us the scourge that you threaten us with. Do so if you are 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 So when they saw it as a cloud appearing in the sky advancing towards their valleys, they said: This is a cloud which will give us rain. Nay! it is what you sought to hasten on, a blast of wind in which is a painful punishment, 24 Destroying everything by the command of its Lord, so they became such that naught could be seen except their dwellings. Thus do We reward the guilty people. 25 We had strengthened them as We have not strengthened you, had given them ears and eyes and hearts; but nothing stood them in good stead, neither their ears nor eyes nor hearts, for they rejected the signs of God, and were seized by what they had mocked. 26