Lamdre represents one of the most precious non-canonical literatures of Sakya Tibetan Buddhism. It generally covers esoteric teachings of Mahnuttara-yoga-tantra and Hevajra Tantra. The Lamdre literature is not only the greatest historical evidence of the tradition but the greatest gift of its masters. While exact dates of the Indian masters are not easy to determine, the preservation of their teachings in notes, manuscripts and stories has provided primary sources for the study of this 1400 year old tradition. The Lamdre texts are meditational and practical manuals used by hundreds of ecclesiastics and lay practitioners of the Sakya tradition, constituting a sacred and secret path which past great masters have trodden. Those who are fortunate enough to own a set of Lamdre texts would treat them as most valuable thing and they are taken wherever they may go. Thus these texts are known as "non-detachable" ['bral spas] for practitioners. Works on Lamdre contain sacred oral history, hagiographies of the lineage masters, instructions on esoteric meditation practices of Hevajra Sdhana, numerous commentaries on Hevajra Tantra, and related liturgies on rites and rituals of the Tantra. Traditionally these texts are only accessible to the faithful and fortunate initiates, who are then allowed to practice the meanings of these texts.
