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

(31) Say: Have ye imagined, if Allah should take away your hearing and your sight and seal your hearts, Who is the Allah Who could restore it to you save Allah? See how We display the revelations unto them! Yet still they turn away.

(32) We confound their hearts and their eyes. As they believed not therein at the first, We let them wander blindly on in their contumacy.

(33) That the hearts of those who believe not in the Hereafter may incline thereto, and that they may take pleasure therein, and that they may earn what they are earning.

(34) (It is) a Scripture that is revealed unto thee (Muhammad) - so let there be no heaviness in thy heart therefrom - that thou mayst warn thereby, and (it is) a Reminder unto believers.

(35) And We remove whatever rancour may be in their hearts. Rivers flow beneath them. And they say: The praise to Allah, Who hath guided us to this. We could not truly have been led aright if Allah had not guided us. Verily the messengers of our Lord did bring the Truth. And it is cried unto them: This is the Garden. Ye inherit it for what ye used to do.

(36) Is it not an indication to those who inherit the land after its people (who thus reaped the consequence of evil-doing) that, if We will, We can smite them for their sins and print upon their hearts so that they hear not?

(37) Such were the townships. We relate some tidings of them unto thee (Muhammad). Their messengers verily came unto them with clear proofs (of Allah's Sovereignty), but they could not believe because they had before denied. Thus doth Allah print upon the hearts of disbelievers (that they hear not).

(38) Already have We urged unto hell many of the jinn and humankind, having hearts wherewith they understand not, and having eyes wherewith they see not, and having ears wherewith they hear not. These are as the cattle - nay, but they are worse! These are the neglectful.

(39) They only are the (true) believers whose hearts feel fear when Allah is mentioned, and when His revelations are recited unto them they increase their faith, and who trust in their Lord;

(40) Allah appointed it only as good tidings, and that your hearts thereby might be at rest. Victory cometh only by the help of Allah. Lo! Allah is Mighty, Wise.