HEART !

"In fact, God does not regard your outward form and wealth, but does regard your heart and good deeds." (A Prophetic Saying)
He (the Prophet) said, "He (God) does not regard your (outward) form: therefore in your devising seek you the owner of the heart."
(God says), "I regard you through the owner of the Heart, not because of the (external) marks of prostration (in prayer) and the giving away of gold (in charities)."
Since you have deemed your heart to be the Heart, you have abandoned the search after those who possess the Heart.
The heart into which if seven hundred (heavens) like these Seven Heavens should enter, they would be lost and hidden (from view).
Do not call such fragments of heart as these "the Heart"... (Mathnawi, V/874-78)
Fools venerate the mosque and endeavor to destroy them that have the heart (in which God dwells).
That (mosque) is phenomenal, this (heart) is real, O asses! The (true) mosque is naught but he hearts of the (spiritual) captains.
The mosque that is the inward (consciousness) of the saints is the place of worship for all: God is there. (Mathnawi, II/3139-41)
(But) when the mukhlis [the mukhlis is who worships devotedly] has become mukhlas, he is delivered: he has reached the place of safety and has won the victory. (Mathnawi, II/1329)
The heart leads you into the neighborhood of the men of heart (the saints); the body leads you into the prison of water and earth. (Mathnawi, I/753)
Do you know why the mirror (of your soul) reflects nothing; because the rust is not cleared from its face. (Mathnawi, 1/35)
Which heart does not contain your love, 
It is an infidel, it cannot be a Muslim. 
If a city does not have the grandeur of the king, 
If it is yet to demolish, you consider that heart as demolished... (Rubais, 96)