The word(s) "hearts" appears 132 time(s) in 121 verse(s) in Quran in Mohsin Khan translation.

(61) And when you (Muhammad صلى الله عليه و سلم) recite the Qur'an, We put between you and those who believe not in the Hereafter, an invisible veil (or screen their hearts, so they hear or understand it not).

(62) And We have put coverings over their hearts lest they should understand it (the Qur'an), and in their ears deafness. And when you make mention of your Lord Alone [La ilaha illallah (none has the right to be worshipped but Allah) Islamic Monotheism (توحيد الله)] in the Qur'an, they turn on their backs, fleeing in extreme dislike.

(63) And We made their hearts firm and strong (with the light of Faith in Allah and bestowed upon them patience to bear the separation of their kith and kin and dwellings) when they stood up and said: "Our Lord is the Lord of the heavens and the earth, never shall we call upon any ilah (god) other than Him; if we did, we should indeed have uttered an enormity in disbelief.

(64) And who does more wrong than he who is reminded of the Ayat (proofs, evidence, verses, lessons, signs, revelations, etc.) of his Lord, but turns away from them, forgetting what (deeds) his hands have sent forth. Truly, We have set veils over their hearts lest they should understand this (the Qur'an), and in their ears, deafness. And if you (O Muhammad صلى الله عليه وسلم) call them to guidance, even then they will never be guided.

(65) Verily, those who believe [in the Oneness of Allah and in His Messenger (Muhammad صلى الله عليه وسلم)] and work deeds of righteousness, the Most Gracious (Allah) will bestow love for them (in the hearts of the believers).

(66) With their hearts occupied (with evil things). Those who do wrong, conceal their private counsels, (saying): "Is this (Muhammad صلى الله عليه وسلم) more than a human being like you? Will you submit to magic while you see it?"

(67) Thus it is [what has been mentioned in the above said Verses (27, 28, 29, 30, 31) is an obligation that mankind owes to Allah] and whosoever honours the Symbols of Allah, then it is truly from the piety of the hearts.

(68) Whose hearts are filled with fear when Allah is mentioned and As-Sabirun [who patiently bear whatever may befall them (of calamities)]; and who perform As-Salat (Iqamat-as-Salat), and who spend (in Allah's Cause) out of what We have provided them.

(69) Have they not travelled through the land, and have they hearts wherewith to understand and ears wherewith to hear? Verily, it is not the eyes that grow blind, but it is the hearts which are in the breasts that grow blind.

(70) That He (Allah) may make what is thrown in by Shaitan (Satan) a trial for those in whose hearts is a disease (of hypocrisy and disbelief) and whose hearts are hardened. And certainly, the Zalimun (polytheists and wrong-doers) are in an opposition far-off (from the truth against Allah's Messenger and the believers).