Dharmakaya has been explained by Tibetan and Indian scholars as a dreamless, deep sleep or death-like state in which, apart from the physical or emotional body, the empty mental continuum remains. It is said to be a permanent state of nothingness, but also is the energy of everything that exists. It is an unconditional state that gives rise to all conditional occurrences in the universe.
The dharmakaya is part of the Trikaya (three bodies) doctrine, which is a teaching on the nature and appearances of Buddha. The Yogacara school of Buddhism, a Buddhist belief system that centers on seeing the world through the practice of yoga, solidified these three aspects of the Trikaya to include dharmakaya in 300 C.E.