Pai-chang, who lived during Tang Dynasty China, and was a successor of Master Mazu (Baso), said that there were three levels of Zazen.
The first level, which he equated with Theravadan practice, is non-attachment.
The second level, which he calls ‘the trap of Bodhisattvas’, is when we are no longer attached to non-attachment, but retain a sense of ourselves.
The third level is when the residual sense of self is dropped off, leaving just this is-ness.
In this video John examines this to clarify the meaning as not pointing to a progressive system which we go through, aiming to attain and remain at the ‘highest’ level, but that each level is more like a particular space within this vast hall of practice, and we move freely between these spaces within our actual sitting.