I don't see the mystic experience in terms of oneness--I see it in terms of openness and spaciousness.
Hmm sounds familiar to this reader of Catholic mystical texts, although Catholic mystics combine the language of "oneness" with "openness" and "spaciousness". Methinks you are creating a wee bit of a false dichotomy between the two....
"...All things are too small to hold me,
I am so vast
In the Infinite
I reach for the Uncreated
I have
touched it,
it undoes me
wider than wide
Everything else
is too narrow
You know this well,
you who are also there.
Tighten
to nothing
the circle
that is
the world's things
Then the Naked
circle
can grow wide,
enlarging,
embracing all..."
- Hadewijch, 13th century Beguile and Flemish mystic
"...France and England are mine, from sea to sea;
So firm is my grip,
No one takes up arms against me.
Mine is Saxony, mine is Guascogne,
Mine are Burgundy and all of Normandy.
Mine the kingdom of Prussia and that of Bohemia,
Hibernia and Roumania, Scotland and Frisia.
Mine is Tuscany and the valley of Spoleto
...
Mine is Campagna, the Roman hills, and the plains of Lombardy;
Mine are Sardinia, Cyprus, Corsica, and Crete,
And unknown kingdoms and numberless subjects beyond the seas -
Medes, Persians, Elamites, Syrians and Mongols,
Georgians, Ethiopians, Indians and Muslims
...
Land, fields full of flowers, trees,
Succulent fruits, livestock - all at my command, all mine.
Lakes, rivers, and oceans teeming with fish,
Air, winds, birds - all pay me joyful homage.
Moon and sun, sky and stars, are but minor treasures:
The treasures that make me burst into song
Lie beyond the sky that you can see.
Participating in the essence of all creatures
It can now say, "All things are mine."
The doors open wide, and entering within
The soul becomes one with God,
Possesses what He Possesses. It hears
What it did not hear, sees what it did not know,
Possesses what it did not believe,
Savors that which has no taste.
In losing all, the soul has risen
To the pinnacle of the measureless;
Because it has renounced all
That is not divine,
It now holds in its grasp
The unimaginable Good
In all its abundance,
A loss and a gain impossible to describe.
...
Spiritual poverty, deepest wisdom, you are slave to nothing,
And in your detachment you possess all things.
God does not dwell in a heart that's confined,
And a heart is only as big as the love it holds.
To live as myself and yet not I,
My being no longer my being,
This is a paradox
We cannot pretend to understand!
Spiritual poverty is being attached to nothing, wanting nothing,
And possessing all things in the spirit of freedom..."
- Blessed Jacopone Da Todi (c.1230-1306), Italian Catholic mystic & Franciscan