Don’t try to focus on an observer

Just sit without artifice or constraint in one’s natural state… that’s all.
Don’t try to focus on an observer. This observer is abstract. There is something like a “conscience-witness”. But the witness is, by nature, neutral. The observer’s role is to interpret, judge and fathom something. Let’s say that, when the observer returns to his primary conscience, he loses the notions of values and concepts to become a lucid witness.
Understand things this way : the openness of the Spirit, its transparency, is vacuity. Its luminosity, its knowledge, is lucidity. The boundless experiences of this condition are its unlimited character.
Ultimately, zazen is to remain lucid in the vacuity, in the infinite.