Tao Te Ching Chapter 55

Who is rich in character

Is like a child.

No poisonous insects sting him,

No wild beasts attack him,

And no birds of prey pounce upon him.

His bones are soft, his sinews tender, yet his grip is strong.

Not knowing the union of male and female, yet his organs are complete,

Which means his vigor is unspoiled.

Crying the whole day, yet his voice never runs hoarse,

Which means his (natural) harmony is perfect.

To know harmony is to be in accord with the eternal,

(And) to know eternity is called discerning.

(But) to improve upon life is called an ill-omen;

To let go the emotions through impulse is called assertiveness.

(For) things age after reaching their prime;

That (assertiveness) would be against Tao.

And he who is against Tao perishes young.

Tao Te Ching