كَلَّا ۚ سَنَكْتُبُ مَا يَقُولُ وَنَمُدُّ لَهُۥ مِنَ ٱلْعَذَابِ مَدًّا
Important Words:
کلا (nay) is a particle and signifies, rejection; rebuke; and reprimanding a person for what he has said being untrue. It also signifies that what has been said before is wrong and what follows after is right (Lane).
Commentary:
The verse means to say that disbelievers take pride in their wealth and children but they should know that they will be deprived of all these things and their punishment will be prolonged as was their prosperity prolonged because it was the prolongation of their prosperity that made them proud and arrogant.
The particle kalla (indeed not) signifies rejection, rebuke; and reprimanding a person for what he has said being untrue. It also signifies that what has been said before is wrong and what follows is right (Lane). The words, 'what he says,' refer to the proud talk in which the disbelievers indulge because of their great wealth, power, influence and children.