The Longchen Nyingthig is a Terma, a revealed treasure, which is a cycle of teachings hidden by Padmasambhava during the 8. century and rediscovered by Jigme Lingpa in the 17. century.
The Terma contains profound teachings of Dzogchen (Ati-Yoga in Sanskrit), which help the practitioner to recognize the Buddha nature within everyone and are the heart of the path of spiritual realization.
The path of the Great Perfection, Dzog.pa Chen.po , originated with the master Garab Dorje and other important figures of the lineage, including Padmasambhava, the guru who spread Buddhism in Tibet, and got to the present day in an uninterrupted line of realized practitioners who preserve those instructions.
These teachings have been classified into three categories:
The one of the mind (Sem.de) which explains the natural state of mind,
The one of the space (Long.de) which indicates the non-intellectual approach to the practice
and the essential instructions (Mengak.de) which describe the methods of Trekchöd and Tögel leading directly to the spontaneous state of a Buddha.
The heart of the essential instructions (Mengak.de) is called Nyingthig and in this cycle we find the Vima Nyingthig and the Kandro Nyingthig two different lineages of transmission of the Dzogchen teachings, unified by the great systematizer of the Nyingma school Longchen Rabjam (1308-1364) and subsequently enhanced by Jigme Lingpa.
Jigme Lingpa (1730-1798) was a great yogi and meditator endowed with the highest achievements, an outstanding scholar who wrote several important works; he had numerous visions including Longchenpa who guided him in the revelation of the Dzogchen teachings of the Longchen Nyingthig cycle.
Machig Rinpoche received all the oral transmissions, empowerments and instructions of this cycle of teachings from his root masters, Kyabje Trulshik Rinpoche and Penor Rinpoche.