Explanation:
The word Atman is used in the basic form of awareness, which is the inert energy confined to the living body. In deep sleep this Atman becomes the same cosmic inert energy, which is called as Brahman. The inert body that separates this Atman from the entire cosmic energy is also a form of inert energy alone, since matter is a form of inert energy. Thus in essence, the Atman in deep sleep merges with the entire ocean of cosmic energy. In deep sleep, awareness disappears. This means that the special work of inert energy in the nervous system is stopped since the nervous system is resting. Hence, in deep sleep, only inert energy remains in its original form.
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