In Tibet´s living wisdom tradition, every scripture, every meditation practice and method of training the mind, is passed on from teacher to student, and then internalized until it becomes an integral part of that student´s experience. Dzogchen Longchen Nyingtik, also called The Great Perfection, is part of the Nyingmapa school, which is considered the oldest school within Tibetan Buddhism. Within the tradition there are two kinds of transmissions. kama, or oral lineage, passed on from teacher to student over the centuries, and the miraculous direct lineage of terma or Spiritual Treasures. In the eighth century, Guru Padmasambhava and his consort and great disciple Yeshe Tsogyal hid these spiritual Treasures in order to be discovered at the appropriate moment in later times.
The preliminary practices of the Longchen Nyingtik, The Heart Essence of the Vast Expanse is a spiritual treasure of Longchenpa’s realised mindstream transferred as a mind-treasure in the heart-mind of omniscient Rigdzin Jigme Lingpa (1729-1798). Jigme Lingpa passed it to Jigme Gyalwai Nyugu, since then, it has become one of the most widely learned practices in the Nyingmapa school. (Reference from book “Words of My Perfect Teacher” by Patrul Rinpoche and translated by the Padmakara Translation Group)