30ذٰلِكَ مَبلَغُهُم مِنَ العِلمِ ۚ إِنَّ رَبَّكَ هُوَ أَعلَمُ بِمَن ضَلَّ عَن سَبيلِهِ وَهُوَ أَعلَمُ بِمَنِ اهتَدىٰ(Irfan-ul-Quran)That is but the limit of the working of their knowledge. Verily your Lord fully knows him who has strayed from His path and (also) knows best him who has attained guidance.