ذَلِكَ مَبْلَغُهُم مِّنَ الْعِلْمِ إِنَّ رَبَّكَ هُوَ أَعْلَمُ بِمَن ضَلَّ عَن سَبِيلِهِ وَهُوَ أَعْلَمُ بِمَنِ اهْتَدَى

That is the ultimate reach of their knowledge. Indeed your Lord knows best those who stray from His way, and He knows best those who are [rightly] guided.