The silence of deep sleep (awareness of awareness) is conducive to liberation.
In it the prana or life-force is neither restrained nor promoted, the senses are neither fed nor starved, the perception of diversity is neither expressed nor supressed, the mind is neither mind nor non-mind.
There is no division and hence no effort at abolishing it; it is called the silence of deep sleep, and one who is established in it may or may not meditate.
There is knowledge of what is as it is, and there is freedom from doubt.
It is utter emptiness. It is supportless. It is of the nature of supreme peace, of which it can neither be said that it is real nor that it is unreal.
That state in which one knows "There is no 'I' or 'another', no mind or anything derived from the mind", in which one knows 'I' is but an idea in this universe, and it is really pure existence - that is known as the silence of deep sleep (awareness of awareness).
In that pure existence which is infinite consciousness, where is 'I' or 'another'?
Concise Yoga Vasistha pg 327 - ISBN: 087395954X
They who, though remaining established in equilibrium, do not let their organs function naturally as long as the body is alive, are obstinate and stubborn people.
As long as there is sesame there is oil; as long as there is the body, there are the different moods also. He who rebels against the states that the body is naturally subject to cuts space to pieces with a sword.
The equilibrium of yoga is for the mind, not for the organs of action and their states.
As long as the body lasts, one should let the organs of action perform their appropriate function, though the intellect and the senses remain in a state of equinimity (balance).
Such is the law of nature, to which even the gods are subject.
Concise Yoga Vasistha pg 375 - ISBN: 087395954X
That pure and equinimous state which is devoid of ego-sense and non-ego sense, of the real and the unreal, and which is free, is known as turiya (the fourth state).
It is the state of the liberated sage. It is the unbroken witness consciousness (awareness of awareness).
It is different from the waking and the dream states, which are characterized by movement of thought; it is different from the deep sleep state, which is characterized by inertia and ignorance.
When the ego-sense is abandoned, there arises that perfect state of equilibrium in which the turiya manifests itself.
Hence I tell you O Rama, there is nothing but the turiya. The turiya is the unmodified consciousness, and that alone exists.
Waking, dream and sleep are a state of the mind. When they cease, the mind dies. Satva alone remains - which the yogis aspire to.
This is the conclusion of all scriptures: there is no avidya (ignorance) and no maya (illusion) in reality; Brahman (consciousness) alone exists. Some call it the void, others pure consciousness, others the Lord, and they argue among themselves.
Abandon all these notions. Rest in nirvana without movement of thought, with the mind greatly 'weakened' and the intelligence at peace; rest in the self as if you are deaf, dumb and blind.
Inwardly abandon everything; externally engage yourself in appropriate action. The existence of the mind alone is happiness, the existence of the mind alone is unhappiness.
By remaining unaware of the mind, let all these cease. Remain unaffected by what is attractive and what is unattractive; by just this much of self-effortthis samsara is overcome!
By remaining unaware of pleasure and pain and of even that which lies between the two, you rise abovesorrow.
Just by this little self-effort you attain the infinite.
Concise Yoga Vasistha pg 413 to 414 - ISBN: 087395954X