All things issue from it; all things return to it. To find the origin, trace back the manifestations. When you recognize the children and find the mother, you will be free of sorrow. If you close your mind in judgements and traffic with desires, your heart will be troubled. If you keep your mind from judging and aren't led by the senses, your heart will find peace. Seeing into darkness is clarity. Knowing how to yield is strength. Use your own light and return to the source of light. This is called practicing eternity.
Empty yourself of everything.
Let the mind become still.
The ten thousand things rise and fall while the Self watches their return.
They grow and flourish and then return to the source.
Returning to the source is stillness, which is the way of nature.
Heaven is eternal and Earth everlasting. They can be eternal and everlasting because they do not exist for themselves, And for this reason can exist forever.