Guidance is in the heart.
Allah-Almighty said:Surah Taghabun V.11
﴿ وَمَن يُؤْمِن بِاللَّهِ يَهْدِ قَلْبَهُ ۚ وَاللَّهُ بِكُلِّ شَيْءٍ عَلِيمٌ ﴾
“And whosoever believeth in Allah, He guideth his heart. And Allah is knower of all things.” (64:11 )
And Allah said:Surah Qaf V.37
﴿ شهيدوَهُوَ إِنَّ فِي ذَٰلِكَ لَذِكْرَىٰ لِمَن كَانَ لَهُ قَلْبٌ أَوْ أَلْقَى السَّمْعَ ﴾
“Indeed in that is a reminder for whoever has a heart or who listens while he is present [in mind]. ( 50: 37 )
Negligence is also in the heart
Allah-Almighty said:Surah Al Khaf V.28
﴿ وَلَا تُطِعْ مَنْ أَغْفَلْنَا قَلْبَهُ عَن ذِكْرِنَا وَاتَّبَعَ هَوَاهُ ﴾
“And obey not him whose heart we have made heedless of Our Remembrance, who followeth his own lust.” ( 18:28 )