At-tur, Mount Sinai , Chapter #52, Verses #44-49

44 And if they were to see a piece of the heaven falling down, they would say: "Clouds gathered in heaps!"
45 So leave them alone till they meet their Day, in which they will sink into a fainting (with horror).
46 The Day when their plotting shall not avail them at all nor will they be helped (i.e. they will receive their torment in Hell).
47 And verily, for those who do wrong, there is another punishment (i.e. the torment in this world and in their graves) before this, but most of them know not. (Tafsir At-Tabaree, Vol. 27, Page 36).
48 So wait patiently (O Muhammad SAW) for the Decision of your Lord, for verily, you are under Our Eyes , and glorify the Praises of your Lord when you get up from sleep.
49 And in the night-time, also glorify His Praises, and at the setting of the stars.