3 Preface ذٰلِكَ بِأَنَّهُم آمَنوا ثُمَّ كَفَروا فَطُبِعَ عَلىٰ قُلوبِهِم فَهُم لا يَفقَهونَYusuf AliThat is because they believed, then they rejected Faith: So a seal was set1 on their hearts: therefore they understand not. Cf. 2:7. Their double-dealing has fogged their understanding. In Arabic the heart is taken to be the seat of understanding as well as of affection.