Who am I? OR Just tell how?

The Lord of all,
The knower of all,
The beginning and end of all—
That Self dwells in every human heart.
Look out—it’s gone.
Look in—it’s gone.
Don’t look—it’s gone.
It cannot be remembered,
It cannot be forgotten,
It cannot be grasped be any possible means.
It is beyond all limits and bounds.
It is the pure oneness
where nothing else can exist.

To know it, you must become it!

It is the final resting place of all activity,
peaceful and unchanging,
the ultimate good,
one without a second,
It is the Supreme Self.
It, above all else, should be known.1