63:3
ذَٰلِكَ بِأَنَّهُمْ ءَامَنُوا۟ ثُمَّ كَفَرُوا۟ فَطُبِعَ عَلَىٰ قُلُوبِهِمْ فَهُمْ لَا يَفْقَهُونَ
dhālika bi-annahum āmanū thumma kafarū faṭubiʿa ʿalā qulūbihim fahum lā yafqahūna
That is because they believed, and then they disbelieved; so their hearts were sealed over, and they do not understand.
— Saheeh International
because they professed faith and then rejected it, so their hearts have been sealed and they do not understand.
— M. A. S. Abdel Haleem
That is because they believed, and then disbelieved; therefore their hearts are sealed, so they understand not.
— Muhammad Muhsin Khan & Muhammad Taqi-ud-Din al-Hilali