Al-An'am - 6:125

فَمَن يُرِدِ اللّهُ أَن يَهْدِيَهُ يَشْرَحْ صَدْرَهُ لِلإِسْلاَمِ وَمَن يُرِدْ أَن يُضِلَّهُ يَجْعَلْ صَدْرَهُ ضَيِّقًا حَرَجًا كَأَنَّمَا يَصَّعَّدُ فِي السَّمَاء كَذَلِكَ يَجْعَلُ اللّهُ الرِّجْسَ عَلَى الَّذِينَ لاَ يُؤْمِنُونَ
[6:125]
Therefore (for) whomsoever Allah intends that He would guide him aright, He expands his breast for Islam, and (for) whomsoever He intends that He should cause him to err, He makes his breast strait and narrow as though he were ascending upwards; thus does Allah lay uncleanness on those who do not believe.
Those whom Allah (in His plan) willeth to guide,- He openeth their breast to Islam; those whom He willeth to leave straying,- He maketh their breast close and constricted, as if they had to climb up to the skies: thus doth Allah (heap) the penalty on those who refuse to believe.
And whomsoever it is Allah's will to guide, He expandeth his bosom unto the Surrender, and whomsoever it is His Will to send astray, He maketh his bosom close and narrow as if he were engaged in sheer ascent. Thus Allah layeth ignominy upon those who believe not.