Jñānakīrti (Tib. Ye shes grags pa), an eminent monk of the late Indian Buddhist period, composed the Tattvāvātara (De kho na nyid la ’jug pa, Realizing Reality), of which only a Tibetan translation exists in the Tibetan Tripiṭaka-Tanjur. The treatise is considered an exposition of the Mahāmudrā teachings, with the chapter entitled “Practices of the Secret Mantra Approach” (gSang sngags kyi sgo’i spyod pa) forms a large part. However, this part has been less frequently discussed. This chapter guides the practice of Mahāmudrā non-dual yoga, which is intended for practitioners with superior faculties. The core content of this chapter can be subsumed under the following two aspects: Mahāmudrā teachings involve practicing insight (prajñā), which represents the theory of meditation, i.e., the idea of emptiness (śūnyatā); it also involves practicing skillful means (upāya), which includes the methods of cultivation, such as tantric rituals such as Vajradhātu maṇḍala visualization. From the perspective of compositional length, the first half of the text contains numerous quotations of verses, with several being from Nāgārjuna’s Mūlamadhyamakakārikā, while the second half mainly draws references from the Tattvasaṃgrahatantra and the Guhyasamājatantra. More attention should be paid to the juxtaposition of the Mahāmudrā teachings with the Tattvasaṃgrahatantra and the Guhyasamājatantra, which reflect the early form of the Mahāmudrā teachings as they were introduced into Tibetan Buddhism.
Chenye Lu (Sat,) studied this question.