Lao Tzu

The (state of) vacancy should be brought to the utmost degree,
and that of stillness guarded with unwearying vigour.

All things
alike go through their processes of activity, and (then) we see them
return (to their original state).

When things (in the vegetable
world) have displayed their luxuriant growth, we see each of them
return to its root.

This returning to their root is what we call the
state of stillness; and that stillness may be called a reporting that
they have fulfilled their appointed end.
[Lao Tzu, The Tao Te Ching]