The book examines the nature of jhanas - states of deep meditative absorption, characterized by detachment from worries and the veils of the world of sensory desires. The book places special emphasis on a clear distinction between mundane and supramundane jhānas. Thus, the four jhanas and the four immaterial achievements first appear as worldly states of deep tranquility, helping to form the basis of concentration necessary for the emergence of wisdom. But when the jhanas are directly related to liberating wisdom, they are called supramundane, transcendental jhanas, the object of contemplation of which is nibbana itself. The author emphasizes that the serenity, bliss and happiness emanating from the state of the jhanas makes it easier to endure the suffering of this world. Thus, for the Buddha, throughout his path, the jhanas remained his heavenly abodes, places of spiritual repose from the hardships of samsara.