Quran 17:46 Al-Isra, ayah 46 of 111

وَجَعَلْنَا عَلَىٰ قُلُوبِهِمْ أَكِنَّةً أَن يَفْقَهُوهُ وَفِىٓ ءَاذَانِهِمْ وَقْرًا ۚ وَإِذَا ذَكَرْتَ رَبَّكَ فِى ٱلْقُرْءَانِ وَحْدَهُۥ وَلَّوْا۟ عَلَىٰٓ أَدْبَـٰرِهِمْ نُفُورًا ۝٤٦

17:46 And We place upon their hearts veils lest they should understand it, and in their ears a deafness; and when thou makest mention of thy Lord alone in the Qur'an, they turn their backs in aversion.