وَجَعَلْنَا مِنۢ بَيْنِ أَيْدِيهِمْ سَدًّا وَمِنْ خَلْفِهِمْ سَدًّا فَأَغْشَيْنَٰهُمْ فَهُمْ لَا يُبْصِرُونَ

And We have made before them a barrier and a barrier behind them, then We have covered them over so that they do not see.