Overall meaning : Even if these idolaters were to see fragments of the sky falling down on them, they would still say, out of sheer stubbornness, ‘These are but piled-up clouds,’ totally denying them to be divine punishment. Therefore, leave them, Muhammad, until they encounter that day of theirs on which they will be punished—the day when their schemes will be of no avail to them, nor will they be helped and saved from the punishment. And there surely awaits those who wrong themselves by disbelieving in Allah another punishment even prior to the punishment on that day, yet most of them are not aware of it!
So be patient with your Lord’s decree, Muhammad; for you are always under Our Watchful Eyes, giving you full support and protection. Extol your Lord’s limitless glory and praise by declaring Him free from all defects and imperfections when you rise up from sleep, and extol His glory during some parts of the night, and at the declining of the stars (when the night is about to end).