The Great Perfection, also known as the Atiyoga or Dzogchen (rDzogs chen), is a tradition of esoteric Buddhism that propounds instantaneous enlightenment and was first brought to Tibet in the Eighth Century of the Common Era. The Indian manuscripts of this tradition have been lost in time. Only the Tibetan translations remain. The original teachings of this tradition are contained in Tantras, which are generally divided into three categories: The Mind Section, the Space Section, and the Upadesha Instruction Section. The Upadesha Instruction section is devoted to the pointing out instructions or practical advice in the understanding and application of the Great Perfection. It is generally described as having seventeen root scriptures. The Tantras here translated is among these seventeen works.
The Tantra on the Six Spaces of the All Good takes us to a world where communication is both verbal and telepathic, recording the communications between the All Good One and a gathering of Bodhisattvas. The Tantra is divided into six chapters, one for each of the six classes of living beings: the gods, the asuras, the humans, the animals, the hungry ghosts, and the hells, while the content of the chapters themselves corresponds to six spaces of wisdom or reality. The Tantra demonstrates a pure vision of the realms of existence, showing them to be essentially good.
I have included images of the Tibetan manuscript for your convenience and to help preserve this ancient literature.