“The Greek term hesychia means a state of silence, stillness, or tranquility, as a result of the cessation of external trouble and internal agitation. Cassian’s ‘purity of heart’ contains the aspect of ‘tranquility of mind’ and thus, the idea of hesychia. The term also means solitude or retreat. Hermits and cenobites alike seek hesychia as an essential value, but in the earliest sources, the term ‘hesychast’ usually denotes a monk living in solitude, or hermit.”

Wong, Joseph. “The Threefold Good: Romualdian Charism and Monastic Tradition.” in Belisle, Peter-Damian, editor. The Privilege of Love: Camaldolese Benedictine Spirituality. Collegeville, MN: Liturgical Press, 2002, pp. 87-88