In Shobogenzo Zuimonki (2-26), Dogen Zenji said that Reuin and Kyogen attained realisation through their bodies. I would say so too did Tozan. What I think Dogen meant is that the body is the field of pure sensation (for example, Kyogen’s sound of something struck) rather than the field of the cognitive interpretation of that sensation (“Oh, my broom flicked up a tile that hit the bamboo and made that noise!”). In the body, each moment of immanent felt-presence is composed of infinite sensations. When I look holistically at a moment of felt-presence, for example during zazen, it’s “not-two” and it’s “not-one”. It is thusness, which is to say that I can’t say what it is. This is to attain understanding through the body. I have to intervene with an act of cognitive interpretation, to articulate sensation as an experience of “this and “that”, “here” and “there”, “now” and “then”, etc.