From Taming the Mind: Discourses of the Buddha (WH 51), edited by the Buddhist Publication Society, (Kandy: Buddhist Publication Society, 1983).
"Monks, I know not of any other single thing so intractable as the untamed mind. The untamed mind is indeed a thing untractable.
"Monks, I know not of any other thing so tractable as the tamed mind. The tamed mind is indeed a thing tractable.
"Monks, I know not of any other single thing so conducive to great loss as the untamed mind. The untamed mind indeed conduces to great loss.
"Monks, I know not of any other single thing so conducive to great profit as the tamed mind. The tamed mind indeed conduces to great profit.
"Monks, I know not of any other single thing that brings such woe as the mind that is untamed, uncontrolled, unguarded and unrestrained. Such a mind indeed brings great woe.
"Monks, I know not of any other single thing that brings such bliss as the mind that is tamed, controlled, guarded and restrained. Such a mind indeed brings great bliss."