﴿ ذَٰلِكَ بِأَنَّهُمْ ءَامَنُوا۟ ثُمَّ كَفَرُوا۟ فَطُبِعَ عَلَىٰ قُلُوبِهِمْ فَهُمْ لَا يَفْقَهُونَ ﴾

“this, because [they profess that] they have attained to faith, whereas [inwardly] they deny the truth - and so, a seal has been set on their hearts so that they can no longer understand [what is true and what false].”

(That) which I have mentioned regarding the hypocrites (is because they believed) outwardly, (then disbelieved) and became firm in their disbelief inwardly, (therefore their hearts are sealed) as a punishment for their disbelief and hypocrisy (so that they understand not) the Truth or guidance.