Mandukya Upanishad

Peace Invocation (Shanti Mantra): Om! O Gods, may we hear with our ears what is auspicious; O worshipful ones, may we see with our eyes what is auspicious. With steady limbs and bodies praising You, may we attain the full span of life allotted by the Divine. May our minds be directed towards the auspicious. Om, Peace, Peace, Peace.

Harih Om! The syllable OM is all this—everything that exists. Its further explanation is this: What was, what is, and what shall be in the future—all this is verily OM. And whatever else transcends the three divisions of time—that too is verily OM alone.

All this is indeed Brahman. This very Self (Atman) is Brahman. This Self has four quarters (modes of manifestation).

The first quarter is Vaishvanara, operating in the waking state (Jagrat), whose consciousness is directed outward toward external objects, who possesses seven limbs and nineteen mouths, and who experiences gross physical objects.

The second quarter is Taijasa, operating in the dream state (Svapna), whose consciousness is directed inward toward subtle mental impressions, who also possesses seven limbs and nineteen mouths, and who experiences subtle inner impressions.

That state where the sleeper desires no objects whatever, and sees no dreams at all, is deep dreamless sleep (Sushupti). Operating in the state of deep sleep, unified into an undifferentiated mass of consciousness, filled with unalloyed peace and bliss, experiencing bliss, whose mouth is consciousness itself—this is Prajna, the third quarter.

This (Prajna/Causal state) is the Sovereign Lord of all; this is the All-Knower; this is the Indwelling Witness; this is the Source and Womb of everything, the origin and the dissolution of all created beings.

Turiya (The Fourth) is not that which is conscious of the inner subjective world, nor that which is conscious of the outer objective world, nor that which is conscious of both, nor a mass of consciousness, nor simple consciousness, nor unconsciousness. It is unperceived by senses, beyond empirical transactions, ungraspable, without distinctive marks, unthinkable, indescribable, whose essence is the conviction of the One Self alone, the cessation of all cosmic plurality, peaceful, auspicious, and non-dual. That is the Self (Atman); That is what must be realized!

This very Self, from the viewpoint of the sacred syllable, is OM. Looked at from the standpoint of phonological measures (matras), the quarters of the Self are the measures of the sound, and the measures of the sound are the quarters—namely, the letter 'A', the letter 'U', and the letter 'M'.

Vaishvanara, dwelling in the waking state, is the first letter 'A', because of pervasiveness (Apti) or being the first (Adimattva). He who realizes this truth verily obtains all desires and becomes foremost among all.

Taijasa, dwelling in the dream state, is the second letter 'U', because of intermediate elevation (Utkarsha) or intermediate position between waking and sleeping (Ubhayatva). He who knows this elevates the continuum of spiritual knowledge, becomes impartial to all, and in his lineage no one is born ignorant of Brahman.

Prajna, dwelling in the state of deep dreamless sleep, is the third letter 'M', because of measuring (Miti) or dissolving (Apiti) all thoughts into unity. He who knows this measures the true nature of all existence and dissolves all multiplicity into the One.

The Fourth (Turiya) is without sound-measure (Amatra), beyond worldly transactions, the dissolution of all relative cosmic manifestation, supremely auspicious (Shiva), and non-dual (Advaita). Thus OM is verily the Self. He who knows this merges his individual self into the Supreme Universal Self by means of the Self.