We’re like a tree with roots, a base, and a trunk. Every leaf, every branch, depends on the roots to absorb nutrients from the soil and send them up to nourish the tree.
Our body, plus our words and deeds, our senses of sight, hearing, smell, taste, and feeling, are like the branches, leaves, and trunk. The mind is like the roots absorbing nutrients and sending them up the trunk to the leaves and branches so that they flower and bear fruit.
– Ajahn Chah, Theravada, Thai Forest Tradition.