Sleep is very necessary for every living being. Without sleep, man as well as other beings cannot live. Of all the joys that the world provides, sleep is the most rewarding. All the rest are arid and dry, trivial and wasteful. When a living being sleeps, the five vital airs - Prana, Apana, Vyana, Udana, Samana - do function along with the five fires in the body conferring warmth. The inhalation and exhalation of the breath proceed serenely, as the Samana in a serene Vedic series. The 'Prana' vital air acts like aahavaneeya fire (consecrated fire perpetually burning in the household) of the Vedic rite. It energises us in the same steady manner. Vyana is as the Dakshinagni lit on the southern side of the altar in the Vedic rite. Udana helps the mind to "reach the Brahma-loka which the person has earned by his Karma to attain." In other words, it enables the person to experience the taste of mergence with the Supreme. For, that which rests in sleep, is happy during sleep, is refreshed by sleep and derives Bliss while sleeping is the Jivi, the embodied Atma. The Jivi is the deity enshrined in the body, its temple. The Jivi experiences all that is seen, heard and contacted by the mind in the outer world, as well as the impact of all that it could not see, hear or contact by the mind. Besides these, the Jivi might construct and experience in dreams and witness such experiences undergone during previous lives. It depends on the activities stamped on the mind of each one. Or, it might happen sometimes, the person gives up at one stroke the association with the body and the senses and gets immersed and lost in his basic principle - the Param-Atma, the Omniself. The Bliss that fills the Jivi is the authenticity of the Param-Atma.

During dreamless sleep, the Jivi enters and revels in the Anandaloka, the region of Bliss, led thereto by the splendour of the Udana prana, the vital air that elevates. That region is known also as Brahma Loka, the Ananda Loka. This is the splendid chance that man gets effortlessly during sleep, the chance to enjoy the proximity of the Param-Atma which is the prime source and substance of the five Basic Elements, the five senses and the Inner Instrument of Awareness - the Five Bhutas, the Five Indriyas and the Antahkarana.

But this experience doesn't last; it is quite temporary. The person who has gained the Awareness through the purification of the mind and the clarification of Buddhi (Intellect) will have the unchanging Bliss of Mergence in Param-Atma. He alone can become omniscient, who is ever in the region of Akshaya (undecaying), merged in the Akshara (imperishable) Parabrahma (the Supreme Vastness), the Param-Atma. When he is aware that all is He, that there is nothing without him or outside Him, he becomes all or Brahman.

In deep sleep, the Jivi is in the thamo guna or dull ignorance. To the realised person, however, even dreams will award as much bliss as the consciousness does while awake. Even when awake, this person gets rid of the impact of the body-sense-reason complex and is saturated with the bliss of his authentic Reality. The particularised self shares the chaithanya or Consciousness of the Universal and it can merge only in that Param-Atma, the Supreme Chaithanya. Therefore, this Sutra emphasises for us the truth that the 'Sath' or 'Is-ness' (which 'becomes' and 'subsumes' all creation) refers only to Para-Brahman, the Supreme Consciousness and not to any entity derived from it and dependent on it.