Surah Al-An'am 6:125

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

So whoever Allāh wants to guide - He expands his breast to [contain] Islām; and whoever He wants to send astray - He makes his breast tight and constricted as though he were climbing into the sky. Thus does Allāh place defilement upon those who do not believe.

Translation: Saheeh International

Tafsir

Whomever God desires to guide He expands his breast to Islam by casting into his heart a light which it the heart expands for and accepts as reported in a hadīth; …

Excerpt from Tafsir al-Jalalayn, commentary on 6:125, via Quran.com. The reader has the full commentary and 9 more tafsirs.