there is no one to turn back and reverse His decision.
"And He is swift in reckoning," meaning: in punishment. When He intends to punish a people among those who belied their messengers, His punishment of them is faster than the blinking of an eye. By this, He strikes fear into the polytheists.
لَا رَاجِعَ يَرُدُّ حُكْمَهُ.
﴿وَهُوَ سريع الْحساب﴾ يَعْنِي: الْعَذَابَ؛ إِذَا أَرَادَ أَنْ يُعَذِّبَ قَوْمًا مِنَ الَّذِينَ كَذَّبُوا رُسُلَهُمْ كَانَ عَذَابُهُ إِيَّاهُمْ أَسْرَعَ مِنَ الطَّرْفِ؛ يُخَوِّفُ بِهَذَا الْمُشْرِكِينَ.
