Upanishad Vahini
Aithareya Upanishad

Freedom from delusion results in vision of Atma
This Upanishad is incorporated in the Rig-veda. It shines bejeweled by six chapters, which describe the absolute Atmic principle. It is therefore famous as the Atmic Six (Atma-Shatka). It makes possible for the aspirant the vision of the Atma that results from the destruction of delusion and ignorance. “Atma” is used in two ways:
worldly activity and supreme. Used in the activity sense, Atma indicates the individual (jivi); in every individual, the Atma expresses itself through the senses of perception (jnanen-driyas) into the outer world. The word is derived from the root ath, which indicates “expansion, consumption, movement”, among other things. So, the word Atma denotes universal immanence, universal assimilation, and perpetual movement. That is to say, it connotes the Brahman itself.
Atma is unlimited, endless, changeless, all
In the waking stage, the Atma, in the sense of the individual (jivi) in worldly activity, enjoys all the experiences.
In the dream stage, all the senses of perception and action hold back their activities, but the Atma creates its own forms and names on the basis of experiences and impressions collected from the outer world. In the “deep sleep” stage, it becomes immanent everywhere and assumes its basic role of pure bliss, unaware of anything outside or inside.
The meaning of the world is in conformity with the experience of the three stages. On account of the apparent limitation in time, space, and condition, the Atma is also taken to be conditioned and limited, but that is not its real nature. It is beginningless, changeless, endless. It knows all, it can achieve all. It has no attributes. It is eternal, unsullied, conscious, free. It has no second; it is unique, whole, without parts.
Atma existed before Creation
The external world is cognised through direct perception, etc. Therefore, all that is capable of being pointed out as this or that, or of being indicated by a name or a form, is subsumed by the idea of “creation (srishti)”. Creation means an act, a result. What then was before that act?
Idam agre, Atma eva aseeth.
Before this, the Atma alone was
The world was a latent product; later it becomes patent. In the latent stage, it was unmanifest in the Atma itself. When the urge to manifest appeared, the multiplicity of names blossomed forth, and all this variety arose to view. Being perceptible by the senses - this is the test of manifestation.
Name is fundamentally sound, manifesting as word. In the statement “this is Ranga”, when the sound Ranga is produced, the listener turns to the person indicated and identifies him as Ranga. The word and its meaning are inseparable. The two were both nonexistent before creation. Therefore, the Atma and the unmanifested creation (jagath) were unreachable by the intelligence and the world that it fashions. After creation, since name and form became the essence of all this, everything can be grasped by words and meaning. The non-dual that was, is, and will be is the Atma. The multiple manifestation of variety proliferating in name and form is the creation. But, basically, it is just one unique substance (vasthu).
Atma is devoid of all distinctions and beyond the reach of senses
The one uniform ocean appears as foam, bubble, wave, and wavelet; so too, creation made manifest the apparent manifoldness from the changeless One. Manifoldness is due to myopia, ignorance. There is no need to posit a second entity other than the Atma. The ignorance or myopia or illusion (maya) is but a product of the will of the Atma. It is not distinct from the Atma. Strength is not distinct from the strong person, is it? The Atma is devoid of distinctions, from the same kind, from different species, or from one’s own characteristic. It is categorically declared as one only.
But it doesn’t become clear so soon that all this is one. The idea is just like the rope appearing as the snake, or the deluding mirage; the Atma also misleads us as creation (jagath). It is all a magician’s trick, manipulated by the wish of the absolute. The rope is the prime cause for the illusion of the snake on the rope. The Atma is beyond the reach of the senses; it has no limbs or body. Only the explanation that it is all an unreal illusion can satisfy the critic who questions how creation can emanate from the Atma, which is pure consciousness only.
Everything is Atma, even the deluding illusion (maya) of variety. It is so strong that it causes execution of deeds through instruments like the sensory organs; you then declare that it is your will and power that did that deed, though it is the delusion that was manifested by Atma that accomplished it.
Atma governs the “deities” of the senses
The world thus created is devoid of consciousness, so it has to be fostered like a machine (yantra). How can a machine operate after its manufacture, and even installation, without a mechanic or machinist? He created the first incarnation of Brahman (Virat-Purusha) out of the five elements; He also endowed that first incarnation with head and limbs. Like the figure of clay made by the potter from earth dug up by him, that first incarnation was produced from the elements. From the limbs of that perfect Person, the world-rulers (loka-palakas) were created.
Then, each sense was separated and equipped with an appropriate deity. In front, the face, the mouth, with Agni as the deity of speech (the function of the mouth), the nose, and the eyes; in this manner, the senses and their respective deities were created and assigned.
These deities bless the senses and see that they function properly. The external appearance of the eye, the nose, and the ear may be quite right, but without the help of the presiding deity, they may not function at all. The cow and the horse were created from the waters and offered to the gods. But the gods were still discontented, so, to answer their prayers, human beings were created similar to the first incarnation of Brahman (Virat-Purusha).
Since that human being was associated with discrimination (viveka), the gods were delighted. All bodies other than the human are merely instruments for experiencing the fruits of action. The human is the only instrument for liberation.
Lord illumines everything through living beings
The Lord, after entering the body, becomes the ruler of the conjunction of the senses and the mind with the objective world. Like an actor, He contacts the outer world and experiences all the lessons of the previous births.
In the presence of the Lord, the ballet-dancer intellect (buddhi) dances her steps, keeping to the timing of the senses and moving from one object to another.
Thus, the Lord illumines everything through the form of the individual living being (jivi). The Supreme Atma (Paramatma), who is limited as the individual soul (jiva-atma), has three areas of recreation: the eye, throat, and heart. The eyes shine with a special splendour when the realisation of Brahman is achieved or even attempted.
This is an evident fact. When the individual has earned the knowledge of its reality, it may not be able to describe how all is nothing besides Atma; but it will achieve the knowledge that Brahman itself is appearing as all this.
One who delves deep into the unity of the individual and the Brahman has certainly discovered the goal of life; there is no doubt of that.
The stages of wakefulness, dream, and deep sleep are unrelated to the Atma. They are concerned only with the physical sensory causes and effects.
Human beings have three forms of birth
Every human being has two bodies: one’s own and that of the progeny. The duties of study, teaching, repetition of the name - these assigned tasks are handed down by parent to child at the time of death, and they are carried on by the child as the representative of the parent and on their behalf. The parent leaves the body and assumes another, one that is more in conformity with the actions and tendencies cultivated and established in this birth. That is the third birth of the parent. The first three mantras speak about the two births, the physical and the spiritual. Now, a third one is added; the continuation by the child.
Sage Vamadeva understood the true nature of Atma in this form and became liberated from all the constant flux of the objective world.
Selected Excerpts From This Discourse