Al-Mursalat 77:11

فَإِذَا النُّجُومُ طُمِسَتْ

So when the stars are obliterated

وَإِذَا السَّمَاءُ فُرِجَتْ

And when the heaven is opened

وَإِذَا الْجِبَالُ نُسِفَتْ

And when the mountains are blown away

لِأَيِّ يَوْمٍ أُجِّلَتْ

For what Day was it postponed?

لِيَوْمِ الْفَصْلِ

For the Day of Judgement.

وَمَا أَدْرَاكَ مَا يَوْمُ الْفَصْلِ

And what can make you know what is the Day of Judgement?