Vajrasattva ［金剛薩埵］ (;  Kongōsatta): The first patriarch in the lineage of transmission of Esoteric Buddhism according to the True Word ( Shingon) school. In that school’s tradition, he is said to have received the teachings of Esoteric Buddhism directly from Mahāvairochana Buddha. Vajrasattva is often called “Master of Secrets” in Chinese Buddhist scriptures. The Mahāvairochana Sutra takes the form of questions and answers between Vajrasattva, an aspirant to wisdom, and Mahāvairochana Buddha. According to the esoteric tradition, Vajrasattva heard Mahāvairochana Buddha expound the esoteric teachings, which he then compiled in the form of scripture and sealed in an iron tower in southern India. This tower, it is said, was opened several centuries later by Nāgārjuna (c. 150–250), at which time Vajrasattva appeared and transferred Esoteric Buddhism to him.