وَإِذَا مَا أُنزِلَتْ سُورَةٌ نَّظَرَ بَعْضُهُمْ إِلَى بَعْضٍ هَلْ يَرَاكُم مِّنْ أَحَدٍ ثُمَّ انصَرَفُوا صَرَفَ اللَّهُ قُلُوبَهُم بِأَنَّهُمْ قَوْمٌ لَّا يَفْقَهُونَ

Whenever a surah is sent down they look at one another: ‘Is anybody observing you?’ Then they slip away. Allah has turned aside their hearts, for they are a people who do not understand.