Tao Teh Ching Chapter 16

致虚极，守静笃。万物并作，吾以观复。夫物芸芸，各复归其根。归根曰静，静曰复命。复命曰常，知常曰明。不知常，妄作凶。
知常容，容乃公，公乃全，全乃王，王乃天，天乃道，道乃久，没身不殆。

Translation
Realize the ultimate void, keep oneself at rest and steady. The countless creatures are all eager to move into actions, however I am here only to see their return (to where they come from). For those creatures, they grow like the rampant weed, only to return to their own root. To return to the root is to be at rest, to be at rest is to return the mission; To return the mission is said to know the unchangeable; To know the unchangeable is to be wise. Those who do not know the unchangeable will only do evil in vain.
To know the unchangeable is to be patient, unhurried and graceful; To be graceful one becomes gentleman; to be a gentleman results in completeness in turn a king of himself; To be a king he reaches on high; to be close to heaven he knows the Tao, which is perpetual, he is then not afraid of losing this body.


Comments
The man with the Tao is an observer. He observes the world in function but is not part of it. Therefore Lao Tzu first said: 致虚极，守静笃. To sit still, to be at rest, don't panic. He said, look around, every creature has his day. Even the longest living tree die after a thousand years. What ever they do, there is one thing that is not escapable, they will die and will return the root. Then why do you go out and strive to do all things? To do all these is not to 知常, the unchangeable. What is the unchangeable? The unchangeable is the fact that sooner or later we will return to the root or source. Not knowing it, you will 妄作凶, do evil in vain. 妄, have a few meanings. It can mean mistaken, random, or erroneous. To this point I have to mention the current American president George W. Bush. He is the ultimate example of not knowing the unchangeable, and therefore the evils he had done are doomed to be in vain.
The second paragraph deals with the unchangeable and the Tao. In fact, because the unchangeable is the dying of the body, knowing and accepting it will result in overcome of fear of the very fact of losing the body.

笃, slow and steady paced movement of a horse.
芸, A kind of herb. In here it mean to grow.
容,从容 to be relaxed and graceful, not in a hurry to finish something.