Ven. Anzan Hoshin Roshi (The Straight Path: Zen Teachings on the
Foundations of Mindfulness)
And how, monks, does somone here view the body as body? Here,monks, one goes into the forest, to the roots of a tree, or to an empty room, sits down cross-legged and holds the body upright, keeping minfulness present.
Breathing in, one is mindful; breathing out one is mindful. Breathing out a long breath one understands "I breath out a long breath." Breathing out a short breath, one understands "I breathe out a short breath."....
One practices "I will breath out with full experience of the whole body." One practices "I will breath in with full experience of the whole body." One practices "I breath out calming the tendancies of the body" One practices "I breath in claming the tendancies of the body"
Just as a skillful turner or a turner's apprentice, making along turn knows "I am making a long turn,"or making a short turn knows "I am making a short turn," just so monks, the monk practices breathing out a long breath knowing "I breathe out a long breath..."
And moreover, monks, in walking one knows "I am walking;" in standing one knows "I am standing;" in sitting one knows "I am sitting." when lying down one knows "I am lying down." In whatever way the body is held, thus the body is understood.
And further, monks, in gooing forwards and in going back, complete knowing is realized. In looking ahead and looking behind, complete knowing is realized. Bending and stretching, complete knowing is realized. Carrying the robes and bowl, complete knowing is realized. In eating and drinking, chewing and tasting, complete knowing is realized. Excreting and urinating complete knowing is realized. In motion and in stillness, in sitting, in sleeping and waking, in speech and silence, complete knowing is realized.
Thus one lives completely viewing the body as body internally; one lives completely viewing the body as body externally. Thus one lives completely viewing the body as body both internally and externally.
One dwells observing the body as phenomena which arise; one dwells observing the body as phenomena which decay. Thus one dwells, observing the body as phenomena which both arise and decay.
When mindfulness "this is body" is established, there is just knowing and just minfulness.