When we sit, our aim is to manifest vast unitary awareness – unitary like space.
This awareness is not the property of the self yet the self appears within it, along with all beings and all phenomena.
If this awareness becomes fractured or partial, we return the attention to this body and this breath.
Not because this body and this breath is the subject or the object of zazen, but because this body and this breath is simply the most accessible to us, like a mountain in its upliftedness, feeling it is a part of the great Earth.