3ذٰلِكَ بِأَنَّهُم آمَنوا ثُمَّ كَفَروا فَطُبِعَ عَلىٰ قُلوبِهِم فَهُم لا يَفقَهونَHilali & KhanThat is because they believed, then disbelieved, therefore their hearts are sealed, so they understand not.