Peace,
Here are some examples of the heart in the Qur'an:
Surah 22:
46. What do they travel on earth to have hearts to understand, and ears to hear? Because
it is not the eyes that blind themselves, but, it is the hearts in the breasts that blind themselves.
54. And so that those to whom knowledge has been given know that (the Quran) is indeed, the Truth coming from your
Lord, let them believe in it, and let their hearts submit to it in all humility. Allah guides to the right
those who believe.
to believe with the heart,
the heart trembles,
the heart hardens,
the heart doubts,
heart sealed, the heart deviates, the heart turns away.
The heart is tranquilized,
the heart leans,
the heart empty,
to penetrate the heart,
the heart denies.
Allah sealed hearts, hearing, and eyes.
We have put sails on their hearts, so that they do not understand it.
We have strengthened their hearts.
their distracted hearts
is inspired by the piety of hearts.
their hearts are full of fear.
their hearts remain ignorant of this.
hearts will be upset as well as looks.
Is there a disease in their hearts? or do they doubt?
Allah seals the hearts of those who do not know.
No blame on you for what you do by mistake, but (you will be blamed for) what your hearts are doing deliberately.
when hearts go up to the throats, terrified (or anxious).
He threw fear into their hearts.
Allah knows, however, what is in your hearts.
the fear will be removed from their hearts,
then their skins and their hearts soothe the remembrance of Allah.
the hearts of those who do not believe in the hereafter and when we mention those who are outside Him, they rejoice.
Our hearts are veiled against what you call us, our ears are deaf.
Surah 47:
16. And some of them are listening to you. Once out of your house, they say to those who have received science: "What did he say, sometimes? "These are the ones whose hearts Allah has sealed and who follow their own passions.
24. Do not they meditate on the Qur'an? Or are there padlocks on their hearts?
They say with their tongues what is not in their hearts.
And it has been embellished in your hearts.
... in their hearts the fury, the fury of ignorance.
Allah has felt the hearts for godliness.
faith has not yet penetrated your hearts.
their hearts humble at the mention of Allah and before what came down from the truth [the Koran].
put in the hearts of those who followed him sweetness and meekness.
He prescribed faith in their hearts and He helped them with His help.
and do not feel in their hearts any desire.
and put in our hearts no rancor for those who believed.
their hearts are divided.
Allah deflected their hearts
Surah 63
3. It is because in truth they believed, and rejected the faith. Their hearts, therefore, have been sealed, so that they understand nothing.
If you repent to Allah it is because your hearts have fallen.
Surah 79:
8. On that day, there will be hearts that will be frightened,
Surah 86:
9. The day when hearts will reveal their secrets,