When we say ‘body’, there is often an unconscious dualism. The standard dualism is body/mind, but this is supported by ingrained habits within our language.
So, we often talk about ‘head and body’ ; the idea that our body is our torso and limbs. If someone touches our face, we think of it differently to someone touching our back. We think of our ‘head’ resting on our ‘body’, and so on.
This does several things, none of them good. By identifying part of the body as ‘the body’, we create a distance and we objectify. We reinforce a sense that ‘I’ am an indeterminate confection of head, brain and mind, and that the ‘I’ is separate from ‘the body’.
To counter this, and with partcular reference to the body in zazen, it is very helpful to give particular attention to the aliveness of our head and neck: our tongue, the roof of our mouth, the pulsing of our eyes and forehead, the musculature of our jaw and neck, and so on. Attention to this flows into attention to the whole body.
The Whole Body of vast expression. Within which is ‘the mind’.