The word(s) "heart" appears 213 time(s) in 195 verse(s) in Quran in Abdullah Yusuf Ali translation.

(51) Many are the Jinns and men we have made for Hell: They have hearts wherewith they understand not, eyes wherewith they see not, and ears wherewith they hear not. They are like cattle,- nay more misguided: for they are heedless (of warning).

(52) For, Believers are those who, when Allah is mentioned, feel a tremor in their hearts, and when they hear His signs rehearsed, find their faith strengthened, and put (all) their trust in their Lord;

(53) Allah made it but a message of hope, and an assurance to your hearts: (in any case) there is no help except from Allah: and Allah is Exalted in Power, Wise.

(54) Remember He covered you with a sort of drowsiness, to give you calm as from Himself, and he caused rain to descend on you from heaven, to clean you therewith, to remove from you the stain of Satan, to strengthen your hearts, and to plant your feet firmly therewith.

(55) Remember thy Lord inspired the angels (with the message): "I am with you: give firmness to the Believers: I will instil terror into the hearts of the Unbelievers: smite ye above their necks and smite all their finger-tips off them."

(56) O ye who believe! give your response to Allah and His Messenger, when He calleth you to that which will give you life; and know that Allah cometh in between a man and his heart, and that it is He to Whom ye shall (all) be gathered.

(57) Remember in thy dream Allah showed them to thee as few: if He had shown them to thee as many, ye would surely have been discouraged, and ye would surely have disputed in (your) decision; but Allah saved (you): for He knoweth well the (secrets) of (all) hearts.

(58) And obey Allah and His Messenger; and fall into no disputes, lest ye lose heart and your power depart; and be patient and persevering: For Allah is with those who patiently persevere:

(59) Lo! the hypocrites say, and those in whose hearts is a disease: "These people,- their religion has misled them." But if any trust in Allah, behold! Allah is Exalted in might, Wise.

(60) Against them make ready your strength to the utmost of your power, including steeds of war, to strike terror into (the hearts of) the enemies, of Allah and your enemies, and others besides, whom ye may not know, but whom Allah doth know. Whatever ye shall spend in the cause of Allah, shall be repaid unto you, and ye shall not be treated unjustly.