The word(s) "heart" appears 161 time(s) in 147 verse(s) in Quran in Mohsin Khan translation.

(51) The hypocrites fear lest a Surah (chapter of the Qur'an) should be revealed about them, showing them what is in their hearts. Say: "(Go ahead and) mock! But certainly Allah will bring to light all that you fear."

(52) So He punished them by putting hypocrisy into their hearts till the Day whereon they shall meet Him, because they broke that (covenant with Allah) which they had promised to Him and because they used to tell lies.

(53) They are content to be with those (the women) who sit behind (at home). Their hearts are sealed up (from all kinds of goodness and right guidance), so they understand not.

(54) The ground (of complaint) is only against those who are rich, and yet ask exemption. They are content to be with (the women) who sit behind (at home) and Allah has sealed up their hearts (from all kinds of goodness and right guidance) so that they know not (what they are losing).

(55) The building which they built will never cease to be a cause of hypocrisy and doubt in their hearts unless their hearts are cut to pieces. (i.e. till they die). And Allah is All-Knowing, All-Wise.

(56) Allah has forgiven the Prophet (صلى الله عليه وسلم), the Muhajirun (Muslim emigrants who left their homes and came to Al-Madinah) and the Ansar (Muslims of Al-Madinah) who followed him (Muhammad صلى الله عليه وسلم) in the time of distress (Tabuk expedition), after the hearts of a party of them had nearly deviated (from the Right Path), but He accepted their repentance. Certainly, He is unto them full of Kindness, Most Merciful.

(57) But as for those in whose hearts is a disease (of doubt, disbelief and hypocrisy), it will add suspicion and doubt to their suspicion, disbelief and doubt; and they die while they are disbelievers.

(58) And whenever there comes down a Surah (chapter from the Qur'an), they look at one another (saying): "Does any one see you?" Then they turn away. Allah has turned their hearts (from the light) because they are a people that understand not.

(59) And if every person who had wronged (by disbelieving in Allah and by worshipping others besides Allah) possessed all that is on the earth and sought to ransom himself therewith (it will not be accepted), and they would feel in their hearts regret when they see the torment, and they will be judged with justice, and no wrong will be done unto them.

(60) Then after him We sent Messengers to their people. They brought them clear proofs, but they would not believe what they had already rejected beforehand. Thus We seal the hearts of the transgressors (those who disbelieve in the Oneness of Allah and disobey Him).