Longchen Nyingthig (Tibetan: ཀློང་ཆེན་སྙིང་ཐིག་, Wylie: klong chen snying thig) is a systematic explanation of Dzogchen within the Nyingma school of Tibetan Buddhism. Like the world famous Bardo Thodol, the Longchen Nyingthig is a seminal example of the terma tradition. The Longchen Nyingthig is generally classified as a Vajrayana or tantric Buddhist esoteric teaching and has an extensive meditational, trance and ritual practice, oral tradition and tantric literature associated with it.
Thondup & Talbott (1996: xiii) state
Longchen Nyingthig (the heart-essence of infinite expanse, or the ultimate truth of the universal openness) is a cycle of mystical teachings that represent the innermost meditation of Dzogpa Chenpo, revealed by the great scholar and adept Jigme Lingpa (1730-1798). Jigme Lingpa discovered them as a "mind ter" (or "mind treasure"), teachings that were discovered from the enlightened nature of the mind.
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