Surah Az-Zumar 39:22

أَفَمَن شَرَحَ ٱللَّهُ صَدْرَهُۥ لِلْإِسْلَـٰمِ فَهُوَ عَلَىٰ نُورٍ مِّن رَّبِّهِۦ ۚ فَوَيْلٌ لِّلْقَـٰسِيَةِ قُلُوبُهُم مِّن ذِكْرِ ٱللَّهِ ۚ أُو۟لَـٰٓئِكَ فِى ضَلَـٰلٍ مُّبِينٍ

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.

Translation: Saheeh International

Tafsir

Is he whose breast God has opened to Islam and becomes guided so that he follows a light from his Lord …? like he whose heart He has sealed with disbelief? — this understanding of the ellipsis is indicated by what follows. …

Excerpt from Tafsir al-Jalalayn, commentary on 39:22, via Quran.com. The reader has the full commentary and 9 more tafsirs.