The Four Stations of Samadhi, or emptiness:
Sixth ground: Infinite Space.
Meditation with characteristics was used until this point but now meditation without characteristics becomes predominant, and continues in the next three grounds.
Seventh ground: The Far-Reaching Ground or Infinite Consciousness.
At this level the seventh consciousness breaks its attachment to the eighth consciousness as being the "self" and is transformed into the wisdom of Equality.
In the first through seventh grounds, "...the sixth and seventh consciousnesses [are being) transformed into their respective wisdom's."
Eighth ground: The Unmoving Ground or Nothing Whatsoever.
Here all outflows "from the sixth and seventh consciousness'es [stop]... and the wisdom of Wonderful Contemplation proceeds spontaneously...."
Ninth ground: Neither Cognition nor Non-cognition.
In this ground is the samadhi of the extinction of feeling and cognition.