215. That which is perceived by something else has for its witness the latter. When there is no agent to perceive a thing, we cannot speak of it as having been perceived at all.
216. This Atman is a self-cognised entity because It is cognised by Itself. Hence the individual soul is itself and directly the Supreme Brahman, and nothing else.
217. That which clearly manifests Itself in the states of wakefulness, dream and profound sleep; which is inwardly perceived in the mind in various forms as an unbroken series of egoistic impressions; which witnesses the egoism, the Buddhi, etc., which are of diverse forms and modifications; and which makes Itself felt as the Existence-Knowledge-Bliss Absolute; know thou this Atman, thy own Self, within thy heart.
218. Seeing the reflection of the sun mirrored in the water of a jar, the fool thinks it is the sun itself. Similarly the stupid man, through delusion, identifies himself with the reflection of the Chit caught in the Buddhi, which is Its superimposition.
219. Just as the wise man leaves aside the jar, the water and the reflection of the sun in it, and sees the self-luminous sun which illumines these three and is independent of them;
220-222. Similarly, discarding the body, the Buddhi and the reflection of the Chit in it, and realising the Witness, the Self, the Knowledge Absolute, the cause of the manifestation of everything, which is hidden in the recesses of the Buddhi, is distinct from the gross and subtle, eternal, omnipresent, all-pervading and extremely subtle, and which has neither interior nor exterior and is identical with one self - fully realising this true nature of oneself, one becomes free from sin, taint, death and grief, and becomes the embodiment of Bliss. Illumined himself, he is afraid of none. For a seeker after Liberation there is no other way to the breaking of the bonds of transmigration than the realisation of the truth of one's own Self.
Source: Vivek Choodamani by Adi Shankaracharya