Al Munafiqun Ayah 3

ذَٲلِكَ بِأَنَّهُمْ ءَامَنُواْ ثُمَّ كَفَرُواْ فَطُبِعَ عَلَىٰ قُلُوبِهِمْ فَهُمْ لَا يَفْقَهُونَ ٣ This is because they believed and then abandoned faith. Therefore, their hearts have been sealed, so they do not comprehend.