Surat Al-Israa (The Night Journey) - الإسراء

وَإِذَا قَرَأْتَ ٱلْقُرْءَانَ جَعَلْنَا بَيْنَكَ وَبَيْنَ ٱلَّذِينَ لَا يُؤْمِنُونَ بِٱلْءَاخِرَةِ حِجَابًا مَّسْتُورًا ﴿٤٥﴾ وَجَعَلْنَا عَلَىٰ قُلُوبِهِمْ أَكِنَّةً أَن يَفْقَهُوهُ وَفِىٓ ءَاذَانِهِمْ وَقْرًا وَإِذَا ذَكَرْتَ رَبَّكَ فِى ٱلْقُرْءَانِ وَحْدَهُۥ وَلَّوْا۟ عَلَىٰٓ أَدْبَٰرِهِمْ نُفُورًا﴿٤٦﴾

And when you recite the Quran, We place between you and those who do not believe in the hereafter a hidden barrier; And We have placed coverings on their hearts and a heaviness in their ears lest they understand it, and when you mention your Lord alone in the Quran they turn their backs in aversion.