"Love's adoration like a mystic seer
Through vision looks at the invisible,
In earth's alphabet finds a godlike sense;
But the mind only thinks, "Behold the one
For whom my life has waited long unfilled,
Behold the sudden sovereign of my days.
Heart feels heart, limb cries for answering limb;
All strives to enforce the unity all is." 
from Sri Aurobindo's SAVITRI 

OM - the matrix of all the various sounds

"There are hundreds of words for God.
One thought is connected with a thousand words; the idea "God" is
connected with hundreds of words, and each one stands as a symbol for God.
Very good. But there must be a generalisation among all these words, some
substratum, some common ground of all these symbols, and that which is the
common symbol will be the best, and will really represent them all. In
making a sound we use the larynx and the palate as a sounding board. Is
there any material sound of which all other sounds must be manifestations,
one which is the most natural sound? Om (Aum) is such a sound, the basis
of all sounds. The first letter, A, is the root sound, the key, pronounced
without touching any part of the tongue or palate; M represents the last
sound in the series, being produced by the closed lips, and the U rolls from
the very root to the end of the sounding board of the mouth. Thus, Om
represents the whole phenomena of sound - producing. As such, it must be
the natural symbol, the matrix of all the various sounds. It denotes the whole
range and possibility of all the words that can be made. Apart from these
speculations, we see that around this word Om are centred all the different
religious ideas in India; all the various religious ideas of the Vedas have
gathered themselves round this word Om." excerpted from RAJA YOGA
by Swami Vivekananda

Turiya Atman

"...the ancient Rishis arrived at what they believed to be the fundamental laws respectively of spiritual, psychical and elemental evolution: Spiritually, the beginning of all things is the Turiya Atman, spirit in its fourth or transcendental state, intellectually unknowable and indefinable, infinite, indivisible, immutable, and supra-conscious. This Turiya Atman may be imaged as the infinite ocean of spirit which evolves in itself spiritual manifestations and workings by that process of limitation or selection on which all creation or manifestation depends. By this Turiya Atman there is conceived or there is selected out of its infinite capacity a state of spirit less unknowable and therefore less indefinable, in which the conceptions of finity and division pre-exist in a potential state and in which consciousness is self-gathered and as yet inoperative. This state of Spirit is called variously Avyakta, the unmanifestation, or the seed-condition or the condition of absolute sleep, because as yet phenomena and activity are not manifest but pre-exist gathered together and undeveloped, just as all the infinite potentialities of organic life upon earth pre-exist gathered together and undeveloped in the protoplasm; just as leaf and twig, trunk and branches, sap and pith and bark, root and flower and fruit pre-exist, gathered together and undeveloped in the seed. The State of Sleep may be envisaged as Eternal Will and Wisdom on the brink of creation, with the predestined evolution of a million universes, the development of sun and star and nebula and the shining constellations and the wheeling orbits of satellite and planet, the formation of metals and the life of trees, the motions and actions of fish and bird and beast and the infinite spiritual, mental and physical stir and activities of man already pre-ordained, pre-arranged and pre- existent, before Time was or. Space existed or Causality began. The Spirit in this state of Sleep is called Prajna, the Wise One or He who knows and orders things beforehand. The next state of Spirit, evolved out of Prajna, is the pure psychical or Dream-State in which Spirit is in a condition of ceaseless psychical activity imagining, willing, selecting out of the matter with which Prajna provides and creating thought-forms to clothe the abundant variety of its multitudinous imaginations. The Dream-State is the psychical condition of Spirit and operates in a world of subtle matter finer and more elastic than gross physical matter and therefore not subject to the heavy restrictions and slow processes with which the latter is burdened. For this reason while physical workings are fixed, slow and confined by walls within walls, thought, psychical manifestation and other operations in subtle matter are in comparison volatile, rapid and free, reacting more elastically against the pressure of Time, Condition and Space. This State of Dream may be envisaged as Eternal Will and Energy in the process of creation, with the whole activity of the Universe teeming and fructuating within it; it is that psychical matrix out of which physical form and life are evolved and to which in sleep it partially returns so that it may recuperate and drink in a fresh store of psychical energy to support the heavy strain of physical processes in gross matter. Spirit in the middle or Dream-State is called Taijasa or Hiranyagarbha, the Shining Embryon. It is Taijasa, Energy of Light and Hiranya the Shining because in psychical matter luminous energy is the chief characteristic, colour and light predominating over fluid or solid form. It is Garbha, Embryon because out of psychical matter physical life and form are selected and evolved into the final or Waking-State in which Spirit manifests itself as physically visible, audible and sensible form and life, and arrives at last at an appearance of firm stability and solidity in gross matter. Spirit in the Waking- State is called Vaiswanor, the Universal Male, He who informs and supports all forms of energy in this physical universe; for it is a root idea of Hindu philosophy that Spirit is the Male which casts its seed into Matter and Matter the female Energy which receives the seed and with it creates and operates. Spirit and Matter are not different entities, but simply the positive and nega- tive poles in the creative operation of the All-Selfor Universal which evolves in Itself and out of Itself the endless procession of things."

from Works of Sri Aurobindo
THE KARMAYOGIN: A COMMENTARY ON THE ISHA UPANISHAD PART II -
KARMAYOGIN THE IDEAL