Therefore, it could be said: What is meant with heart is the same “Celestial Jewel” which controls the degree of human-ness within a human being : The heart possesses such exalted position in the Holy Qur’an that it is mentioned when the topic of revelation i.e. communication between God and men is discussed.
God-Almighty said to Holy Prophet (S): نَزَلَ بِهِ الرُّوحُ الْأَمِينُ عَلَىٰ قَلْبِكَ لِتَكُونَ مِنَ الْمُنذِرِينَ “Which is the true spirit hath brought down, upon the heart, that thou mayest be (one) of the warners.” (26:193-194) And said: قُلْ مَن كَانَ عَدُوًّا لِّجِبْرِيلَ فَإِنَّهُ نَزَّلَهُ عَلَىٰ قَلْبِكَ بِإِذْنِ اللَّهِ “Say (O Muhammad, to mankind) who is enemy to Gabriel!
For he it is who hath revealed (this scripture) to thy heart by God's leave.” (2:97) The heart's position is so eminent that it sees the revealing angel and hears his voice. God-Almighty has said: فَأَوْحَىٰ إِلَىٰ عَبْدِهِ مَا أَوْحَىٰ مَا كَذَبَ الْفُؤَادُ مَا رَأَىٰ “And He revealed unto His slave () that which he revealed.
The Heart lied not (in seeing the angel) what it saw.” (53:10-11) Soundness and Sickness of Heart Our living depends upon spirit and heart because, they are the ones who manage the bodies. All the parts of the body obey their command and all deeds and action initiate from the heart. Therefore, the salvation and cruelty of a person depends upon his hearts condition.
It has been inferred from the Holy Qur’an and narrations that like the human bodies which are healthy and sick at different times, his heart's condition may also follow the same cycle (i.e. some times it is healthy while at other times it is sick). God-Almighty in Holy Qur’an said: يَوْمَ لَا يَنفَعُ مَالٌ وَلَا بَنُونَ إِلَّا مَنْ أَتَى اللَّهَ بِقَلْبٍ سَلِيمٍ “The day when wealth and sons avail not (any man).
Save him who bringeth unto God a whole heart“ (26: 88-89) And said: إِنَّ فِي ذَٰلِكَ لَذِكْرَىٰ لِمَن كَانَ لَهُ قَلْبٌ “Lo! therein verily is a reminder for him who hath a heart” (50:37) And said: وَأُزْلِفَتِ الْجَنَّةُ لِلْمُتَّقِينَ غَيْرَ بَعِيدٍ هَٰذَا مَا تُوعَدُونَ لِكُلِّ أَوَّابٍ حَفِيظٍ مَّنْ خَشِيَ الرَّحْمَٰنَ بِالْغَيْبِ وَجَاءَ بِقَلْبٍ مُّنِيبٍ “And the Garden is brought nign for those who kept from evil, no longer distant.