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.

Sura al-Naḥl 16:106

مَن كَفَرَ بِٱللَّـهِ مِنۢ بَعْدِ إِيمَٰنِهِۦٓ إِلَّا مَنْ أُكْرِهَ وَقَلْبُهُۥ مُطْمَئِنٌّۢ بِٱلْإِيمَٰنِ وَلَٰكِن مَّن شَرَحَ بِٱلْكُفْرِ صَدْرًا فَعَلَيْهِمْ غَضَبٌ مِّنَ ٱللَّـهِ وَلَهُمْ عَذَابٌ عَظِيمٌ

man kafara billāhi min baʿdi īmānihi illā man ukriha wa-qalbuhu muṭmaʾinnun bi-l-īmāni wa-lākin man sharaḥa bil-kufri ṣadran faʿalayhim ghaḍabun mina allāhi wa-lahum ʿadhābun ʿaẓīmun

Any one who, after accepting faith in Allah, utters Unbelief,- except under compulsion, his heart remaining firm in Faith - but such as open their breast to Unbelief, on them is Wrath from Allah, and theirs will be a dreadful Penalty.

Sura Ṭā Hā 20:25

قَالَ رَبِّ ٱشْرَحْ لِى صَدْرِى

qalā rabbi ishraḥ lī ṣadrī

(Moses) said: "O my Lord! expand me my breast;

Sura al-Zumar 39:22

أَفَمَن شَرَحَ ٱللَّـهُ صَدْرَهُۥ لِلْإِسْلَٰمِ فَهُوَ عَلَىٰ نُورٍ مِّن رَّبِّهِۦ فَوَيْلٌ لِّلْقَٰسِيَةِ قُلُوبُهُم مِّن ذِكْرِ ٱللَّـهِ أُو۟لَٰٓئِكَ فِى ضَلَٰلٍ مُّبِينٍ

a-fa-man sharaḥa allāhu ṣadrahu lil-islāmi fa-huwa ʿalā nūrin min rabbihi fa-waylun lil-qāsiyati qulūbuhum min dhikri allāhi ulāʾika fī ḍalālin mubīnin

Is one whose heart Allah has opened to Islam, so that he has received Enlightenment from Allah, (no better than one hard-hearted)? Woe to those whose hearts are hardened against celebrating the praises of Allah! they are manifestly wandering (in error)!