Longchen Rabjam is considered the most realized and erudite Master in the history of the ancient Nyingma school of Tibetan Buddhism, and the Dzogchen line in particular. He wrote over 270 texts, of which his writings on Dzogchen are best known, especially the collection of texts in which he elucidates the tantras of Great Perfection. Among this collection, called the "Seven Treasures of Longchenpa," the most outstanding is this text - "The Precious Treasury of Dharmadhatu." This is the first text from the most secret Section of the Instructions of Dzogchen Mengak-de (Upadesh), published publicly in Russian, and the deepest of all published books on Buddhism.