The Aitareya Upanishad

May my speech be one with my mind, and may my mind be one with my speech.
O thou self-luminous Brahman, remove the veil of ignorance from before me, that I may behold thy light.
Do thou reveal to me the spirit of the scriptures.
May the truth of the scriptures be ever present to me.
May I seek day and night to realize what I learn from the sages.
May I speak the truth of Brahman.
May I speak the truth.
May it protect me.
May it protect my teacher.
Om. Peace—peace—peace.

Before creation, all that existed was the Self, the Self alone. Nothing else was. Then the Self thought. “Let me send forth the worlds.”

He sent forth these worlds: Ambhas, the highest world, above the sky and upheld by it; Marichi, the sky; Mara, the mortal world, the earth; and Apa, the world beneath the earth.

He thought: “Behold the worlds. Let me now send forth their guardians.” Then he sent forth their guardians.

He thought: “Behold these worlds and the guardians of these worlds. Let me send forth food for the guardians.” Then he sent forth food for them.

He thought: “How shall there be guardians and I have no part in them?

“If, without me, speech is uttered, breath is drawn, eye sees, ear hears, skin feels, mind thinks, sex organs procreate, then what am I?’

He thought: “Let me enter the guardians.” Whereupon, opening the center of their skulls, he entered. The door by which he entered is called the door of bliss.

The Self being unknown, all three states of the soul are but dreaming–waking, dreaming, and dreamless sleep. In each of these dwells the Self: the eye is his dwelling place while we wake, the mind is his dwelling place while we dream, the lotus of the heart is his dwelling place while we sleep the dreamless sleep.

Having entered into the guardians, he identified himself with them. He became many individual beings. Now, therefore, if an individual awake from his threefold dream of waking, dreaming, and dreamless sleep, he sees no other than the Self. He sees the Self dwelling in the lotus of his heart as Brahman, omnipresent, and he declares: “I know Brahman!”

Who is this Self whom we desire to worship? Of what nature is this Self?
Is he the self by which we see form, hear sound, smell odor, speak words, and taste the sweet or the bitter?

Is he the heart and the mind by which we perceive, command, discriminate, know, think, remember, will, feel, desire, breathe, love, and perform other like acts?

Nay, these are but adjuncts of the Self, who is pure consciousness. And this Self, who is pure consciousness, is Brahman. He is God, all gods; the five elements—earth, air, fire, water, ether; all beings, great or small, born of eggs, born from the womb, born from heat, born from soil; horses, cows, men, elephants, birds; everything that breathes, the beings that walk and the beings that walk not. The reality behind all these is Brahman, who is pure consciousness.

All these, while they live, and after they have ceased to live, exist in him.
The sage Vamadeva, having realized Brahman as pure consciousness, departed this life, ascended into heaven, obtained all his desires, and achieved immortality.