They had therefore achieved the Wisdom Concentration, and acquired Mind-Created Bodies, which are adorned with mighty supernatural powers. Such bodies are free of any interspaces, bones, or substances, they are like the sun and the moon, like rainbows, electricity, finest gold, luminous pearls, Sphatikas, Pravadas, Hridaras, Campakas, Pavonine Flowers and Moons, and the images from mirrors.
The rainbow body is the physical mastery state of Dzogchen of the Nyingmapa Mantrayana and the Bönpo where the trikaya is in accord and the nirmanakaya is congruent with bodymind and the integrity of the mindstream (the heartmind) is realised as Dharmakaya. The corporeal body of the realised Dzogchenpa which is now hallowed, returns to the pure primordial energetic essence-quality of the Five Pure Lights of the five elemental processes of which it is constituted through phowa and the Bardo of Mahasamadhi or Parinirvana. This is then projected as the mindstream through the process of phowa. The realiser of Jalus resides in the 'once upon a time' time out of time, timeless eternal state that is considered a mystery.
According to Dzogchen lore, the attainment of the Rainbow Body is the sign of complete realisation of the Dzogchen view. As Tenzin Wangyal Rinpoche (2002: p.141) states: “The realised Dzogchen practitioner, no longer deluded by apparent substantiality or dualism such as mind and matter, releases the energy of the elements that compose the physical body at the time of death”.
More specifically, the rainbow body is constituted by the Five Pure Lights. When the view of Dzogchen and the integrity of the mindstream which links the Trikaya is realised prior to the death-Bardo (Skt. antarabhava), the bodymind of the Nirmanakaya (Tib. sprul sku) Dzogchenpa enters samadhi (Tib. ting nge ‘dzin) and commences Phowa or the ‘transferral of consciousness’ into the constituent Five Pure Lights of the Sambhogakaya (Tib. longs sku) to the Dharmakaya, sometimes leaving the non-living faecal matter elements of the bodymind such as hair and nails.
There have been a number of documented sightings of the Jalus process through the Bardo of death which may take a number of days to complete. The bodymind of the Nirmanakaya in samadhi, all the time decreasing its dimentionality as the constituent Five Pure Lights of the mindstream are transmuted into the 'glorious body' of Sambhogakaya.