The witness of the three states of consciousness [waking, dream and deep sleep] and of the nature of Existence-Consciousness-Bliss is the Self
Adi ShankaraYou never identify yourself with the shadows cast by your body, or with its reflection, or with the body you see in a dream or in your imagination. Therefore you should not identify yourself with this living body either.
Adi ShankaraAs gold purified in a furnace loses its impurities and achieves its own true nature, the mind gets rid of the impurities of the attributes of delusion, attachment and purity through meditation and attains Reality.
Adi Shankara