Heaven and Earth last for ever. Why do Heaven and Earth last for ever? They are unborn, so ever living. The sage stays behind, thus he is ahead. He is detached, thus at one with all. Through selfless action, he attains fulfillment.
When you accurately perceive the fluidity of things, you can also begin to perceive the constancy behind them: the creative, transformative, boundless, immutable Tao.
As it acts in the world, the Tao is like the bending of a bow. The top is bent downward; the bottom is bent up. It adjusts excess and deficiency so that there is perfect balance.