In Surah Az-Zumar, ayat 23 Allah azza wa jall says
اللَّهُ نَزَّلَ أَحْسَنَ الْحَدِيثِ كِتَابًا مُّتَشَابِهًا مَّثَانِيَ تَقْشَعِرُّ مِنْهُ جُلُودُ الَّذِينَ يَخْشَوْنَ رَبَّهُمْ ثُمَّ تَلِينُ جُلُودُهُمْ وَقُلُوبُهُمْ إِلَىٰ ذِكْرِ اللَّهِ ۚ ذَٰلِكَ هُدَى اللَّهِ يَهْدِي بِهِ مَن يَشَاءُ ۚ وَمَن يُضْلِلِ اللَّهُ فَمَا لَهُ مِنْ هَادٍ
Allah has sent down the best statement: a consistent Book wherein is reiteration. The skins shiver therefrom of those who fear their Lord; then their skins and their hearts relax at the remembrance of Allah . That is the guidance of Allah by which He guides whom He wills. And one whom Allah leaves astray – for him there is no guide.