Look, it cannot be seen - it is beyond form. Listen, it cannot be heard - it is beyond sound. Grasp, it cannot be held - it is intangible. These three are indefinable, they are one.
From above it is not bright; From below it is not dark: Unbroken thread beyond description. It returns to nothingness. Form of the formless, Image of the imageless, It is called indefinable and beyond imagination.
Stand before it - there is no beginning. Follow it and there is no end. Stay with the Tao, Move with the present.
Knowing the ancient beginning is the essence of Tao.
Lao Tzu has Yin Xi appear to the Barbarian as the Buddha.