Quran english Al Munafiqun 3

ذلك بأنهم آمنوا ثم كفروا فطبع على قلوبهم فهم لا يفقهون

Thalika bi-annahum amanoothumma kafaroo fatubiAAa AAala quloobihim fahum layafqahoon

 
Sahih International
That is because they believed, and then they disbelieved; so their hearts were sealed over, and they do not understand.
Muhsin Khan
That is because they believed, then disbelieved, therefore their hearts are sealed, so they understand not.
Pickthall
That is because they believed, then disbelieved, therefore their hearts are sealed so that they understand not.
Yusuf Ali
That is because they believed, then they rejected Faith: So a seal was set on their hearts: therefore they understand not.
Shakir
That is because they believe, then disbelieve, so a seal is set upon their hearts so that they do not understand.
Dr. Ghali
That is for that they believed; thereafter they disbelieved; then their hearts have been stamped upon, (i.e., sealed) so they do not comprehend.