swami gambhirananda explains that the state where the sleeper does not desire any enjoyable thing and does not see any dream is deep sleep, and prājna is the doorway to the experience of the dream and waking states. "prājña" is the self as the universal person in deep sleep. yajnavlkya tells janaka that "chidaksha", the self of the nature of consciousness, is consciousness behind intelligent sound and the source of shabda brahman whose primary form is aum which word is to be meditated upon as "prajñā" ('knowledge'), the inmost consciousness.