qulub

Qulūb is the plural form of qalb in Arabic, meaning "hearts." In both classical and modern usage, qalb denotes the heart as a physical organ and as the seat of inner life, including emotion, intention, and moral perception. The term qulūb (the hearts) is used to refer to multiple individuals’ inner states or to the concept of hearts collectively.

Etymology and grammar: The word qalb comes from a root associated with turning or changing, reflecting the idea that the heart can turn toward different directions. The plural form qulūb is formed in standard Arabic and appears frequently in religious and literary texts to discuss more than one heart or the inner life of a community.

Usage in Islamic texts: The Qur’an and hadiths frequently present the heart as the locus of faith, guidance, doubt, and spiritual sincerity. Expressions about diseased or hardened hearts describe spiritual ailments, while other passages speak of the heart turning toward God. The term is common in exegesis and theology to analyze how revelation affects the qalb and how divine guidance is received or resisted by human hearts.

Theological and philosophical sense: In many Islamic traditions the qalb is viewed as the central, mutable seat of rational judgment and spiritual insight, distinct from the nafs (self) and ruh (spirit). In Sufism, the qalb can be described as an inner, purifying center that may become illumined through divine knowledge, serving as a medium through which reality is perceived.

Modern usage: In contemporary Arabic, qalb remains the standard word for "heart" in everyday and medical contexts, while qulūb appears in religious, literary, and formal discourse to indicate the inner moral center of people or communities.