The word(s) "heart" appears 169 time(s) in 159 verse(s) in Quran in Muhammad Pickthal translation.

(51) The alms are only for the poor and the needy, and those who collect them, and those whose hearts are to be reconciled, and to free the captives and the debtors, and for the cause of Allah, and (for) the wayfarer; a duty imposed by Allah. Allah is Knower, Wise.

(52) The hypocrites fear lest a surah should be revealed concerning them, proclaiming what is in their hearts. Say: Scoff (your fill)! Lo! Allah is disclosing what ye fear.

(53) So He hath made the consequence (to be) hypocrisy in their hearts until the day when they shall meet Him, because they broke their word to Allah that they promised Him, and because they lied.

(54) They are content that they should be with the useless and their hearts are sealed, so that they apprehend not.

(55) The road (of blame) is only against those who ask for leave of thee (to stay at home) when they are rich. They are content to be with the useless. Allah hath sealed their hearts so that they know not.

(56) The building which they built will never cease to be a misgiving in their hearts unless their hearts be torn to pieces. Allah is Knower, Wise.

(57) The prayer of Abraham for the forgiveness of his father was only because of a promise he had promised him, but when it had become clear unto him that he (his father) was an enemy to Allah he (Abraham) disowned him. Lo! Abraham was soft of heart, long-suffering.

(58) Allah hath turned in mercy to the Prophet, and to the Muhajirin and the Ansar who followed him in the hour of hardship. After the hearts of a party of them had almost swerved aside, then turned He unto them in mercy. Lo! He is Full of Pity, Merciful for them.

(59) But as for those in whose hearts is disease, it only addeth wickedness to their wickedness, and they die while they are disbelievers.

(60) And whenever a surah is revealed, they look one at another (as who should say): Doth anybody see you? Then they turn away. Allah turneth away their hearts because they are a folk who understand not.