About This Teaching
The defilements are in the mind, Ajahn Dtun agrees, but why then contemplate the body? Because the mind clings to the body as self, and from that comes the sense of things belonging to oneself; when those things change, greed, anger and delusion arise. Whatever is clung to brings suffering, so mindfulness and wisdom must be used to let go of clinging to the body.
He points out that the Buddha's four foundations of mindfulness begin with the body, the first of the ten fetters is self-view, and the five khandhas begin with form. He once contemplated only mental states: greed in the morning, anger later in the morning, liking and disliking in the afternoon, letting each go. Yet the next day new sights, sounds, smells, tastes and touches brought new liking and disliking.
It is like a tree with seven branches: cut one on Monday, another on Tuesday, the seventh on Sunday, and by then the first has grown back. To finish the work you must dig out the root so the tree dies. The root is the mind's attachment to the body as self. When the mind sees the body as impermanent and not-self, greed and anger ease and attachment to self lessens. To contemplate the body this way, the mind needs calm as its foundation.