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

(1) And who believe in the Revelation sent to thee, and sent before thy time, and (in their hearts) have the assurance of the Hereafter.

(2) Allah hath set a seal on their hearts and on their hearing, and on their eyes is a veil; great is the penalty they (incur).

(3) In their hearts is a disease; and Allah has increased their disease: And grievous is the penalty they (incur), because they are false (to themselves).

(4) Thenceforth were your hearts hardened: They became like a rock and even worse in hardness. For among rocks there are some from which rivers gush forth; others there are which when split asunder send forth water; and others which sink for fear of Allah. And Allah is not unmindful of what ye do.

(5) They say, "Our hearts are the wrappings (which preserve Allah's Word: we need no more)." Nay, Allah's curse is on them for their blasphemy: Little is it they believe.

(6) And remember We took your covenant and We raised above you (the towering height) of Mount (Sinai): (Saying): "Hold firmly to what We have given you, and hearken (to the Law)": They said:" We hear, and we disobey:" And they had to drink into their hearts (of the taint) of the calf because of their Faithlessness. Say: "Vile indeed are the behests of your Faith if ye have any faith!"

(7) Say: Whoever is an enemy to Gabriel-for he brings down the (revelation) to thy heart by Allah's will, a confirmation of what went before, and guidance and glad tidings for those who believe,-

(8) Say those without knowledge: "Why speaketh not Allah unto us? or why cometh not unto us a Sign?" So said the people before them words of similar import. Their hearts are alike. We have indeed made clear the Signs unto any people who hold firmly to Faith (in their hearts).

(9) So when ye have accomplished your holy rites, celebrate the praises of Allah, as ye used to celebrate the praises of your fathers,- yea, with far more heart and soul. There are men who say: "Our Lord! Give us (Thy bounties) in this world!" but they will have no portion in the Hereafter.

(10) There is the type of man whose speech about this world's life May dazzle thee, and he calls Allah to witness about what is in his heart; yet is he the most contentious of enemies.