It endures until one of them becomes manifest to the heart and settles there, making it its home. The defeat of the other means its expulsion from the heart. As Allah the Exalted has said: "From the evil of the retreating whisperer" (al-Nās 114:4). He (the whisperer) withdraws when Allah is mentioned, but emerges in moments of heedlessness. Only the dhikr (remembrance of God) of Allah expels the army of Satan from the heart, for it cannot remain together with dhikr. (Qudāma, 151)
The qalb (the heart) is used in two senses: First, it is the physical, pinecone-shaped piece of flesh placed in the chest. This is well known. In this sense, the qalb is the locus of the animal soul in both humans and other living beings. Second, it is a rabbānī (divine) subtlety from the spiritual realm. This is the true essence of the human being. It is the one who knows, perceives, and understands. The Exalted Allah has said: "Have they not traveled through the land so that they would have hearts (qulūb) by which to reason?" (al-Ḥajj 22:46). It is the one who earns reward, is subject to punishment, is addressed, and receives address. It has a connection to the physical heart in the body. This is solely a spiritual and divine subtlety, and is related to the heart in the body. (Rawḍa, 110)
Fass also means heart. By making the word fass the subject and the phrase fī kalimat the predicate, the inspired fass of ḥikma (wisdom) is indicated, and then, with the phrase "the other fass mentioned after it," reference is made to ishāra (allusion). Afterwards, by making fass the subject and veiling the phrase fī kalimat (i.e., by bringing a particle before the predicate), it is intended to make the predicate implicit. In this case, the hearts of the prophets are like the bezel of a ring, while their spirits are like the ring in relation to the bezel... (Ṣofyāvī, 12)
The heart of the ʿārif (gnostic) or the insān al-kāmil (perfect human) is like the ring encircling the bezel of a ring. In the place of the ring's bezel, there is nothing superfluous. That place is exactly the size of the bezel. Its roundness, quadrangularity, hexagonality, octagonality, or whatever the shape of the bezel is, so it becomes. The likening of the insān al-kāmil to the ring's circle, rather than anything else, alludes to the cycle of wujūd (existence), that is, beginning from Allah and returning to Him. The comparison of the heart to the ring encircling the bezel indicates that the true aim in man is the heart, as it is the locus of divine manifestations. In this ḥāl (spiritual state), the manifestations occurring in the heart are like the engravings made on the bezel of a ring. Thus, just as what is meant by the ring is the bezel, so too what is meant by the human being is the heart. (Ṣofyāvī, 210)
The heart is a subtlety placed in the heart that gives light. It is the locus of good akhlāq (character), the one who commands good and knows Allah. (Jāmiʿ, 55)
The heart is divided into three. The first is the heart of the common people, which flutters around acts of obedience in the dunyā (world). The second is the heart of the elite, which flutters around the karāma (saintly wonders) of the hereafter. The third is the heart of the elite of the elite, which flutters around intimacy and supplication at the Sidrat al-Muntahā. (Jāmiʿ, 62)
The abode of the nafs (the lower self) is the sharia (the sacred law), the spirit (rūḥ) is from the realm of command, and the heart is the abode of majesty. (Nafahāt, 72)
The heart, like the limbs, also has its own actions. The action of the heart is intention. (Nafahāt, 248)
(See also: ʿaql; nafs; rūḥ)