OM represents all of reality.
Everything that has existed, exists now, or will exist is OM.
Even what lies beyond time is OM.
All of this is ultimate reality.
Your true Self is that same reality.
This Self appears in four aspects.
The first aspect is the waking state.
Here, awareness is directed outward.
You experience the physical world through the senses
and interact with solid, tangible things.
The second aspect is the dream state.
Here, awareness turns inward.
You experience a mental world made of images, memories, and ideas -
things that feel real but are subtle and internal.
The third aspect is deep, dreamless sleep.
In this state, there are no desires, thoughts, or images.
Awareness is unified and peaceful.
There is rest and quiet happiness,
though you are not consciously aware of it at the time.
This deep awareness is the ground of everything.
It knows all experience, governs all experience,
and is where all things arise and return.
The Fourth is not waking, dreaming, or sleeping.
It is not inward awareness or outward awareness.
It is not a mix of the two,
and it is not unconscious either.
It cannot be seen, described, or grasped.
It is beyond thought and beyond language.
It is pure awareness itself,
the quiet background in which all experiences appear and disappear.
It is peaceful, whole, and non-divided.
This is your true Self.
This is what is to be realized.
This same Self is symbolized by OM.
The sounds of OM reflect the different states of consciousness.
The sound "A" represents the waking state,
because waking experience is the starting point of awareness
and includes all ordinary perception.
Understanding this brings confidence and groundedness in life.
The sound "U" represents the dream state,
because it lies between waking and deep sleep
and refines awareness.
Understanding this deepens insight and balance.
The sound "M" represents deep sleep,
because all experiences dissolve into it
and rest there.
Understanding this brings completeness and integration.
What comes after the sounds of OM -
the silence - is the Fourth.
That silence is non-dual awareness.
It is where all experience ends.
It is peaceful and whole.
OM is the Self - Knowing this, one rests fully in what one truly is
Note: OM is pronounced "OM", NOT "A-U-M". The sounds A & U are conjunctive into "O" in the Sanskrit language.