The word ''heart'' in Quran

Heart changes between two worlds of angels and Satan. And this change includes sciences, moods and evolutions. Heart changes in happiness, cheerfulness, sadness and misery. It is permanent in a way and its change depends on province of God. It is said in a Hadith'' the heart of a devout is between two fingers of God and God controls it however he likes.
Heart of human devotes to will and science that other creatures do not have. Purpose from science is recognition of affairs in the world and the doomsday and rational realities because these affairs are beyond senses and are understood by heart or wisdom. Only persons use these two and have ability of promoting spiritually and rationally so that they can achieve rank of angels whereas plants and animals never promote and remain as they already were at first. Purpose from will is recognition of consequences of deeds and recognition of true path through wisdom.
The prophet (peace of Allah be upon him and his descendants) states '' if Satans were not around heart of persons, they would look at the sky''. It is said in a hadith'' there is a piece of meat in body of human and if it is healthy, the whole body will be healthy as well and if it is sick, the whole body will be sick as well, it is heart''.
The prophet (peace of Allah be upon him and his descendants) states '' each heart has two eyes and if God wills happiness ad goodness for a person, he or she will see spirituality''.
God states about persons that have no light of guidance
لَّذِينَ كَانَتْ أَعْيُنُهُمْ فِي غِطَاءٍ عَن ذِكْرِي وَكَانُوا لَا يَسْتَطِيعُونَ سَمْعًا
(Unbelievers) whose eyes had been under a veil from remembrance of Me, and who had been unable even to hear.
Heart is a mine that can be observed. It can observe realities of sciences and deeds. Quran states
إِنَّ فِي ذَٰلِكَ لَذِكْرَىٰ لِمَن كَانَ لَهُ قَلْبٌ أَوْ أَلْقَى السَّمْعَ وَهُوَ شَهِيدٌ
Verily in this is a Message for any that has a heart and understanding or who gives ear and earnestly witnesses (the truth).
Hakin Solatan Muhammad Gonabadi believes that heart has seven faces. Heart is the place of the light of Islam and darkness of blasphemy. Heart is center of faith in God as Quran states
لَّا تَجِدُ قَوْمًا يُؤْمِنُونَ بِاللَّهِ وَالْيَوْمِ الْآخِرِ يُوَادُّونَ مَنْ حَادَّ اللَّهَ وَرَسُولَهُ وَلَوْ كَانُوا آبَاءَهُمْ أَوْ أَبْنَاءَهُمْ أَوْ إِخْوَانَهُمْ أَوْ عَشِيرَتَهُمْ ۚ أُولَٰئِكَ كَتَبَ فِي قُلُوبِهِمُ الْإِيمَانَ وَأَيَّدَهُم بِرُوحٍ مِّنْهُ ۖ وَيُدْخِلُهُمْ جَنَّاتٍ تَجْرِي مِن تَحْتِهَا الْأَنْهَارُ خَالِدِينَ فِيهَا ۚ رَضِيَ اللَّهُ عَنْهُمْ وَرَضُوا عَنْهُ ۚ أُولَٰئِكَ حِزْبُ اللَّهِ ۚ أَلَا إِنَّ حِزْبَ اللَّهِ هُمُ الْمُفْلِحُونَ
Thou wilt not find any people who believe in Allah and the Last Day, loving those who resist Allah and His Messenger, even though they were their fathers or their sons, or their brothers, or their kindred. For such He has written Faith in their hearts, and strengthened them with a spirit from Himself. And He will admit them to Gardens beneath which Rivers flow, to dwell therein (for ever). Allah will be well pleased with them, and they with Him. They are the Party of Allah. Truly it is the Party of Allah that will achieve Felicity.
قَالَتِ الْأَعْرَابُ آمَنَّا ۖ قُل لَّمْ تُؤْمِنُوا وَلَٰكِن قُولُوا أَسْلَمْنَا وَلَمَّا يَدْخُلِ الْإِيمَانُ فِي قُلُوبِكُمْ ۖ وَإِن تُطِيعُوا اللَّهَ وَرَسُولَهُ لَا يَلِتْكُم مِّنْ أَعْمَالِكُمْ شَيْئًا ۚ إِنَّ اللَّهَ غَفُورٌ رَّحِيمٌ
The desert Arabs say, "We believe." Say, "Ye have no faith; but ye (only)say, ´We have submitted our wills to Allah,´ For not yet has Faith entered your hearts. But if ye obey Allah and His Messenger, He will not belittle aught of your deeds: for Allah is Oft-Forgiving, Most Merciful''.
Heart is affection of human as Quran states
وَقَالَ نِسْوَةٌ فِي الْمَدِينَةِ امْرَأَتُ الْعَزِيزِ تُرَاوِدُ فَتَاهَا عَن نَّفْسِهِ ۖ قَدْ شَغَفَهَا حُبًّا ۖ إِنَّا لَنَرَاهَا فِي ضَلَالٍ مُّبِينٍ
Ladies said in the City: "The wife of the (great) ´Aziz is seeking to seduce her slave from his (true) self: Truly hath he inspired her with violent love: we see she is evidently going astray.
Heart is center of seeing unseen lights;
مَا كَذَبَ الْفُؤَادُ مَا رَأَىٰ
. The (Prophet´s) (mind and) heart in no way falsified that which he saw
Blood of heart is center of God affection. It is also center of discoveries and religious sciences. It is center of demonstration of divine names and attributes.
Baba Taher says '' heart is called with this name because of its change and evolution. When it flows, it is a way of science and each science leads to a reality and each reality is a way for God recognition''.
Heart in the following verse means spirits;
إِذْ جَاءُوكُم مِّن فَوْقِكُمْ وَمِنْ أَسْفَلَ مِنكُمْ وَإِذْ زَاغَتِ الْأَبْصَارُ وَبَلَغَتِ الْقُلُوبُ الْحَنَاجِرَ وَتَظُنُّونَ بِاللَّهِ الظُّنُونَا
Behold! they came on you from above you and from below you, and behold, the eyes became dim and the hearts gaped up to the throats, and ye imagined various (vain) thoughts about Allah.
It means understanding and knowing in the following verse;
إِنَّ فِي ذَٰلِكَ لَذِكْرَىٰ لِمَن كَانَ لَهُ قَلْبٌ أَوْ أَلْقَى السَّمْعَ وَهُوَ شَهِيدٌ
Verily in this is a Message for any that has a heart and understanding or who gives ear and earnestly witnesses (the truth).
وَمِنْهُم مَّن يَسْتَمِعُ إِلَيْكَ ۖ وَجَعَلْنَا عَلَىٰ قُلُوبِهِمْ أَكِنَّةً أَن يَفْقَهُوهُ وَفِي آذَانِهِمْ وَقْرًا ۚ وَإِن يَرَوْا كُلَّ آيَةٍ لَّا يُؤْمِنُوا بِهَا ۚ حَتَّىٰ إِذَا جَاءُوكَ يُجَادِلُونَكَ يَقُولُ الَّذِينَ كَفَرُوا إِنْ هَٰذَا إِلَّا أَسَاطِيرُ الْأَوَّلِينَ
Of them there are some who (pretend to) listen to thee; but We have thrown veils on their hearts, So they understand it not, and deafness in their ears; if they saw every one of the signs, not they will believe in them; in so much that when they come to thee, they (but) dispute with thee; the Unbelievers say: "These are nothing but tales of the ancients''.
رَضُوا بِأَن يَكُونُوا مَعَ الْخَوَالِفِ وَطُبِعَ عَلَىٰ قُلُوبِهِمْ فَهُمْ لَا يَفْقَهُونَ
They prefer to be with (the women), who remain behind (at home): their hearts are sealed and so they understand not.
It means courage in the following verse;
وَمَا جَعَلَهُ اللَّهُ إِلَّا بُشْرَىٰ وَلِتَطْمَئِنَّ بِهِ قُلُوبُكُمْ ۚ وَمَا النَّصْرُ إِلَّا مِنْ عِندِ اللَّهِ ۚ إِنَّ اللَّهَ عَزِيزٌ حَكِيمٌ
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.
It means chastity in the following verse;
هُوَ الَّذِي أَخْرَجَ الَّذِينَ كَفَرُوا مِنْ أَهْلِ الْكِتَابِ مِن دِيَارِهِمْ لِأَوَّلِ الْحَشْرِ ۚ مَا ظَنَنتُمْ أَن يَخْرُجُوا ۖ وَظَنُّوا أَنَّهُم مَّانِعَتُهُمْ حُصُونُهُم مِّنَ اللَّهِ فَأَتَاهُمُ اللَّهُ مِنْ حَيْثُ لَمْ يَحْتَسِبُوا ۖ وَقَذَفَ فِي قُلُوبِهِمُ الرُّعْبَ ۚ يُخْرِبُونَ بُيُوتَهُم بِأَيْدِيهِمْ وَأَيْدِي الْمُؤْمِنِينَ فَاعْتَبِرُوا يَا أُولِي الْأَبْصَارِ
It is He Who got out the Unbelievers among the People of the Book from their homes at the first gathering (of the forces). Little did ye think that they would get out: And they thought that their fortresses would defend them from Allah! But the (Wrath of) Allah came to them from quarters from which they little expected (it), and cast terror into their hearts, so that they destroyed their dwellings by their own hands and the hands of the Believers, take warning, then, O ye with eyes (to see).
يَا أَيُّهَا الَّذِينَ آمَنُوا لَا تَدْخُلُوا بُيُوتَ النَّبِيِّ إِلَّا أَن يُؤْذَنَ لَكُمْ إِلَىٰ طَعَامٍ غَيْرَ نَاظِرِينَ إِنَاهُ وَلَٰكِنْ إِذَا دُعِيتُمْ فَادْخُلُوا فَإِذَا طَعِمْتُمْ فَانتَشِرُوا وَلَا مُسْتَأْنِسِينَ لِحَدِيثٍ ۚ إِنَّ ذَٰلِكُمْ كَانَ يُؤْذِي النَّبِيَّ فَيَسْتَحْيِي مِنكُمْ ۖ وَاللَّهُ لَا يَسْتَحْيِي مِنَ الْحَقِّ ۚ وَإِذَا سَأَلْتُمُوهُنَّ مَتَاعًا فَاسْأَلُوهُنَّ مِن وَرَاءِ حِجَابٍ ۚ ذَٰلِكُمْ أَطْهَرُ لِقُلُوبِكُمْ وَقُلُوبِهِنَّ ۚ وَمَا كَانَ لَكُمْ أَن تُؤْذُوا رَسُولَ اللَّهِ وَلَا أَن تَنكِحُوا أَزْوَاجَهُ مِن بَعْدِهِ أَبَدًا ۚ إِنَّ ذَٰلِكُمْ كَانَ عِندَ اللَّهِ عَظِيمًا
O ye who believe! Enter not the Prophet´s houses,- until leave is given you,- for a meal, (and then) not (so early as) to wait for its preparation: but when ye are invited, enter; and when ye have taken your meal, disperse, without seeking familiar talk. Such (behaviour) annoys the Prophet: he is ashamed to dismiss you, but Allah is not ashamed (to tell you) the truth. And when ye ask (his ladies) for anything ye want, ask them from before a screen: that makes for greater purity for your hearts and for theirs. Nor is it right for you that ye should annoy Allah´s Messenger, or that ye should marry his widows after him at any time. Truly such a thing is in Allah´s sight an enormity.
It also means soul in the following verse;
أَفَلَمْ يَسِيرُوا فِي الْأَرْضِ فَتَكُونَ لَهُمْ قُلُوبٌ يَعْقِلُونَ بِهَا أَوْ آذَانٌ يَسْمَعُونَ بِهَا ۖ فَإِنَّهَا لَا تَعْمَى الْأَبْصَارُ وَلَٰكِن تَعْمَى الْقُلُوبُ الَّتِي فِي الصُّدُورِ
Do they not travel through the land, so that their hearts (and minds) may thus learn wisdom and their ears may thus learn to hear? Truly it is not their eyes that are blind, but their hearts which are in their breasts.
يَا أَيُّهَا النَّاسُ إِن كُنتُمْ فِي رَيْبٍ مِّنَ الْبَعْثِ فَإِنَّا خَلَقْنَاكُم مِّن تُرَابٍ ثُمَّ مِن نُّطْفَةٍ ثُمَّ مِنْ عَلَقَةٍ ثُمَّ مِن مُّضْغَةٍ مُّخَلَّقَةٍ وَغَيْرِ مُخَلَّقَةٍ لِّنُبَيِّنَ لَكُمْ ۚ وَنُقِرُّ فِي الْأَرْحَامِ مَا نَشَاءُ إِلَىٰ أَجَلٍ مُّسَمًّى ثُمَّ نُخْرِجُكُمْ طِفْلًا ثُمَّ لِتَبْلُغُوا أَشُدَّكُمْ ۖ وَمِنكُم مَّن يُتَوَفَّىٰ وَمِنكُم مَّن يُرَدُّ إِلَىٰ أَرْذَلِ الْعُمُرِ لِكَيْلَا يَعْلَمَ مِن بَعْدِ عِلْمٍ شَيْئًا ۚ وَتَرَى الْأَرْضَ هَامِدَةً فَإِذَا أَنزَلْنَا عَلَيْهَا الْمَاءَ اهْتَزَّتْ وَرَبَتْ وَأَنبَتَتْ مِن كُلِّ زَوْجٍ بَهِيجٍ
O mankind! if ye have a doubt about the Resurrection, (consider) that We created you out of dust, then out of sperm, then out of a leech-like clot, then out of a morsel of flesh, partly formed and partly unformed, in order that We may manifest (our power) to you; and We cause whom We will to rest in the wombs for an appointed term, then do We bring you out as babes, then (foster you) that ye may reach your age of full strength; and some of you are called to die, and some are sent back to the feeblest old age, so that they know nothing after having known (much), and (further), thou seest the earth barren and lifeless, but when We pour down rain on it, it is stirred (to life), it swells, and it puts forth every kind of beautiful growth (in pairs).
وَالْبُدْنَ جَعَلْنَاهَا لَكُم مِّن شَعَائِرِ اللَّهِ لَكُمْ فِيهَا خَيْرٌ ۖ فَاذْكُرُوا اسْمَ اللَّهِ عَلَيْهَا صَوَافَّ ۖ فَإِذَا وَجَبَتْ جُنُوبُهَا فَكُلُوا مِنْهَا وَأَطْعِمُوا الْقَانِعَ وَالْمُعْتَرَّ ۚ كَذَٰلِكَ سَخَّرْنَاهَا لَكُمْ لَعَلَّكُمْ تَشْكُرُونَ
The sacrificial camels we have made for you as among the symbols from Allah: in them is (much) good for you: then pronounce the name of Allah over them as they line up (for sacrifice): when they are down on their sides (after slaughter), eat ye thereof, and feed such as (beg not but) live in contentment, and such as beg with due humility: thus have We made animals subject to you, that ye may be grateful.
وَمَا أَرْسَلْنَا مِن قَبْلِكَ مِن رَّسُولٍ وَلَا نَبِيٍّ إِلَّا إِذَا تَمَنَّىٰ أَلْقَى الشَّيْطَانُ فِي أُمْنِيَّتِهِ فَيَنسَخُ اللَّهُ مَا يُلْقِي الشَّيْطَانُ ثُمَّ يُحْكِمُ اللَّهُ آيَاتِهِ ۗ وَاللَّهُ عَلِيمٌ حَكِيمٌ
Never did We send a messenger or a prophet before thee, but, when he framed a desire, Satan threw some (vanity) into his desire: but Allah will cancel anything (vain) that Satan throws in, and Allah will confirm (and establish) His Signs: for Allah is full of Knowledge and Wisdom.
وَمَا أَرْسَلْنَا مِن قَبْلِكَ مِن رَّسُولٍ وَلَا نَبِيٍّ إِلَّا إِذَا تَمَنَّىٰ أَلْقَى الشَّيْطَانُ فِي أُمْنِيَّتِهِ فَيَنسَخُ اللَّهُ مَا يُلْقِي الشَّيْطَانُ ثُمَّ يُحْكِمُ اللَّهُ آيَاتِهِ ۗ وَاللَّهُ عَلِيمٌ حَكِيمٌ
Never did We send a messenger or a prophet before thee, but, when he framed a desire, Satan threw some (vanity) into his desire: but Allah will cancel anything (vain) that Satan throws in, and Allah will confirm (and establish) His Signs: for Allah is full of Knowledge and Wisdom.
وَكَأَيِّن مِّن قَرْيَةٍ أَمْلَيْتُ لَهَا وَهِيَ ظَالِمَةٌ ثُمَّ أَخَذْتُهَا وَإِلَيَّ الْمَصِيرُ
And to how many populations did I give respite, which were given to wrong-doing? in the end I punished them. To me is the destination (of all).