From sayings of Ancestor Lu, quoted in:
Vitality, Energy, Spirit: A Taoist Sourcebook (Shambhala Classics)

Translated & edited by Thomas Cleary

How is doing applied? To study its application, one must ask the autonomous mind. The autonomous mind is imbued with great understanding; it observes the changes of movement and stillness of yin and yang, looks to absolute yang and emulates its firm action, looks to absolute yin and communes with its process. The autonomous mind also studies the four seasons and models itself on their cycle. Silently comprehending the ultimate, it plumbs the original source.

Thus extensively observing all processes of creation and evolution, sitting calmly with the mind in trance, the energy of trance exists alone, calm sitting exists alone. Now there is nothing whatsoever in the autonomous mind, and the infant resembling the self that was previously cultivated and crystallized by the alchemical elixir communes with heaven and earth.

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