Surah Az-Zumar, Verse 22

أَفَمَن شَرَحَ ٱللَّهُ صَدۡرَهُۥ لِلۡإِسۡلَٰمِ فَهُوَ عَلَىٰ نُورٖ مِّن رَّبِّهِۦۚ فَوَيۡلٞ لِّلۡقَٰسِيَةِ قُلُوبُهُم مِّن ذِكۡرِ ٱللَّهِۚ أُوْلَٰٓئِكَ فِي ضَلَٰلٖ مُّبِينٍ٢٢

afaman sharaḥa l-lahu ṣadrahu lil'is'lāmi fahuwa ʿalā nūrin min rabbihi fawaylun lil'qāsiyati qulūbuhum min dhik'ri l-lahi ulāika fī ḍalālin mubīnin

So is one whose breast Allāh has expanded to [accept] Islām and he is upon [i.e., guided by] a light from his Lord [like one whose heart rejects it]? Then woe to those whose hearts are hardened against the remembrance of Allāh. Those are in manifest error.