Courtesy of Himalayan Art Resources
Texts by and about Śrī Siṃha (shrI sing+ha/shrI seng+ha), one of the early masters of the Dzogchen lineage:
This short commentary (Tōh. 4353) on the secret mantra or tantric meaning of the famous Heart Sūtra is attributed to the Atiyoga teacher Śrī Siṃha. According to the colophon, he gave this explanation to his disciple Vairocana, who put it into writing and taught it to King Tri Songdetsen.