Ashtavakra Gita 17.10 -

We have three basic states of awareness – the wakeful, sleep and dream states. Wakefulness is external, extensive and manifold. It is common to all, repetitive. Just contrary to this is the sleep state which is concentric and individualistic. One withdraws from wakefulness completely, remains coiled up within, to the utter exclusion of the world, including his own body. Sometimes one slips into dream, which too is individualistic. In dream, he is exposed to a new world, body and objects, which have no connection with the waking world.

Every one passes through these, and is in one of them any time. But the Knower transcends the three states. All the three come under object, whereas he is the Subject. The three states occur in the Substratum ‘I’. The Knower is conscious of the Self, and considers everything else to be its illusory display. He feels no connection with any of them or what transpires therein, just as the sleeper has no connection with dream or the dreamt phenomena, when woken up.

Subject awareness is so much, so exclusive, that the Knower is not able to think of anything else like waking, sleep and dream. Each of the three vanishes. To identify with any of them will be to be vanishing like them. Self-awareness is such that it does not wink or blink. It is ever luminous, effulgent. Once that reigns, the three do not. The Self overwhelms all else and remains singular, un-transforming. It is the supreme state of illumination!