وَجَعَلْنَا مِنۢ بَيْنِ أَيْدِيهِمْ سَدًّا وَمِنْ خَلْفِهِمْ سَدًّا فَأَغْشَيْنَٰهُمْ فَهُمْ لَا يُبْصِرُونَ
Commentary:
The barriers referred to in the verse may be the barriers of usages, prejudices, and pride of disbelievers. They could not look forward to the great and bright future which lay before them if they accepted Islam, and they did not look back to the histories of past peoples who rejected the truth and were seized with Divine punishment. The result of the barriers placed before and behind them was that they themselves became totally devoid of all spiritual light.
On account of the barriers of usages, prejudices and pride the disbelievers could not have looked forward to the great and bright future which lay before them if they accepted Islam, and they did not look back to the histories of past peoples who rejected the truth and were seized with Divine punishment.