qalb

Qalb (Arabic: قلب) is the Arabic term for the heart. It is used to denote both the physical heart and the seat of perception, emotion, and moral orientation in Arabic language and Islamic thought. Etymologically, it comes from the triliteral root Q-L-B, associated with turning or flipping, reflecting the belief that the heart can incline toward different states.

In the Qur'an and in classical Arabic literature, qalb appears as the inner center of awareness and conviction. It is described as capable of faith or disbelief, sincerity or hypocrisy, and it can be softened or hardened by spiritual conditions. The phrase about the softness or hardness of the heart is a common topic in religious discourse.

In Islamic metaphysics and Sufi thought, the qalb is often treated as a locus of spiritual perception that can be purified or illuminated, in contrast to the nafs (self) and the ruh (soul). Purification of the qalb through remembrance, prayer, and ethical conduct is seen as essential for perceiving the divine.

In modern Arabic, qalb remains the standard word for the anatomical heart and is widely used metaphorically in poetry, journalism, and everyday speech. The term has entered many languages via religious, philosophical, and literary texts, and also appears in place names and personal names in some Muslim-majority regions.