Shaykh al-Shanqeeti (may Allaah have mercy on him) said:  

The answer is that Allaah has explained in many verses of His Book those impediments which have been placed on their hearts, ears and eyes, such as seals and veils, have been placed on them as a suitable recompense for their previous kufr and for their disbelieving in the Messengers by choice. So Allaah has turned their hearts away by placing upon them a seal and veils etc, as a punishment for their kufr. Among the aayahs that indicate that is the verse (interpretation of the meaning): 

“Allaah has set a seal upon their hearts because of their disbelief”

[al-Nisaa’ 4:155]

This a clear Qur’aanic text which states that their previous kufr is the reason for the seal upon their hearts. And Allaah says (interpretation of the meaning): 

“So when they turned away (from the path of Allaah), Allaah turned their hearts away (from the Right Path)”

[al-Saff 61:5]

This is also a clear indication that the reason why Allaah has turned their hearts away is their initial turning away. Allaah says (interpretation of the meaning): 

“That is because they believed, and then disbelieved; therefore their hearts are sealed, so they understand not”

[al-Munaafiqoon :3] 

“In their hearts is a disease (of doubt and hypocrisy) and Allaah has increased their disease”

[al-Baqarah 2:10] 

“And We shall turn their hearts and their eyes away (from guidance), as they refused to believe therein for the first time, and We shall leave them in their trespass to wander blindly”

[al-An’aam 6:110]

“Nay! But on their hearts is the Raan (covering of sins and evil deeds) which they used to earn”

[al-Mutaffifeen 83:14]

and there are other aayahs which speak of the seal on their hearts and say that their being prevented from understanding that which may benefit them is a punishment for their previous kufr. What we have mentioned here is a refutation of the specious arguments of the Jabariyyah who continually refer to these aayahs and others from the Holy Qur’aan.