The Tantra on Eliminating All Evil Rebirths is a work belonging to the class of Yoga Tantras. Like many Tantras, the text is presented in the form of a dialogue between the Buddha and an assembly of gods. The chief of these deities, Shakra, asks the Buddha what has happened to the young god Vimalamaniprabha, who has fallen from one of the six Buddhist Heavens, known specifically as the "Heaven of the Thirty-three gods." The Buddha responds that the young god has fallen into the Hell known as Avici ("without respite") where he is undergoing insufferable physical and mental torment. Horrified, the gods ask what can be done to rescue him and other living beings from such an evil destiny. Upon entering into deep meditative concentration, the Buddha proceeds to introduce various rites for pacifying, subjugating and destroying demons, and for attaining happiness and prosperity, as well as a number of other ceremonies disposed to ward off evil and overcome misfortunes threatening both the living and the dead. In the case of the funeral rituals described by the Buddha, the general assumption underlying these rites is that actions performed by surviving relatives necessarily have a positive effect on the condition of the deceased. The series of memorial services is designed essentially to enable individuals to pass safely from one life to the next. The Tantra on Eliminating All Evil Rebirths has from very early on been an important source for Tibetan funeral rituals, both Buddhist and Bon-po (See Section 4).
The Tantric traditions of the oldest school of Tibetan Buddhism, the Nyingma-pa, were introduced to a wider Tibetan religious audience through two primary channels: (1) the "ancient translations," which were derived from the teachings of an elite group of Indian Buddhist mystics, brought to Tibet during the eighth century, and then promulgated through the activities of a large assembly of accomplished Tibetan translators, such as Vairochana, and (2) hidden scriptures called "treasures" or Terma (gter ma), which were texts that had been concealed in unusual and remote locations during times of religious persecution to be preserved and then later rediscovered, usually with the assistance of supernatural beings, at the appropriate time. These two fundamental streams of literature can be found both in the collection of Nyingma Tantras called the Nyingma Gyubum, or "Collected Tantras of the Old School" (rnying ma'i rgyud 'bum), and in the collected translations of Vairochana, the Vairo Gyubum (vairo rgyud 'bum). Among the first category of ancient scripture is included the Tantra on the Bardo State of Becoming. This Tantra represents one of the earliest Tibetan sources on the intermediate bardo period, and includes brief discussions on a number of topics directly relevant to that subject, such as methods for reading correctly the omens of death, the internal and external signs of the dying process, advice on how to take control of the bardo experience, and techniques to avoid an unpleasant rebirth. These topics will be discussed in more detail in later sections of our exhibit.
The Tantra on the Secret Union of Sun and Moon is included among the collected treasures of the Nyingma Gyubum and is also one of the seventeen Tantras associated with the highly esoteric Great Perfection tradition, or Dzokchen (rdzogs chen). The basic plot of the Tantra is structured around a dialogue between the deity Vajradhara and a Bodhisattva ("compassionate hero of enlightenment") named Mitok Tupa (Mi rtog thub pa). Motivated by compassion, Mitok Tupa asks a series of questions concerning the methods living beings may employ to achieve liberation from the ongoing cycle of birth and death. Vajradhara responds by describing systematically the experiences an individual undergoes during the various intermediate bardo periods, and in the process teaches Mitok Tupa how to practice the oral instructions of his spiritual teacher during the present lifetime (referred to as the Bardo of Ordinary Life); how to stabilize his mind during the painful process of dying (the Bardo of Dying); how to achieve Buddhahood through recognition during the intermediate period of Reality's dawning (the Bardo of Reality); and, how to be guaranteed a positive rebirth in a Buddha's Pure Realm while passing into a new existence (the Bardo of Becoming). The message of Vajradhara's teaching is simple and pragmatic. Release from cyclic existence (samsara) can be obtained if one performs the proper ceremonies, follows the necessary meditative instructions, and recognizes the truth taught by ones teacher. The text also provides a detailed ritual program designed to insure an auspicious destiny for both the living and the dead.