Sura al-Anʿām 6:125

فَمَن يُرِدِ ٱللَّـهُ أَن يَهْدِيَهُۥ يَشْرَحْ صَدْرَهُۥ لِلْإِسْلَٰمِ وَمَن يُرِدْ أَن يُضِلَّهُۥ يَجْعَلْ صَدْرَهُۥ ضَيِّقًا حَرَجًا كَأَنَّمَا يَصَّعَّدُ فِى ٱلسَّمَآءِ كَذَٰلِكَ يَجْعَلُ ٱللَّـهُ ٱلرِّجْسَ عَلَى ٱلَّذِينَ لَا يُؤْمِنُونَ

fa-man yuridi allāhu an yahdiyahu yashraḥ ṣadrahu lil-islāmi wa-man yurid an yuḍillahu yajʿal ṣadrahu ḍayyiqan ḥarajan ka-annamā yaṣṣaʿʿadu fī l-samāʾi ka-dhālika yajʿalu allāhu l-rijsa ʿalā lladhīna lā yuʾminūna

Those whom Allah (in His plan) willeth to guide,- He openeth their breast to Islam; those whom He willeth to leave straying,- He maketh their breast close and constricted, as if they had to climb up to the skies: thus doth Allah (heap) the penalty on those who refuse to believe.