One day, Chang-sha Ching-tsen (d. 868), one of the well-known Chinese Ch'an masters, wandered in the mountain. When he was back just at the gate of the temple, the head monk asked him:
-Where have you been, Sir?
Looked at but cannot be seen - it is beneath form;
Listened to but cannot be heard - it is beneath sound;
Held but cannot be touched - it is beneath feeling;
These depthless things evade definition,
And blend into a single mystery.
In its rising there is no light,
In its falling there is no darkness,
A continuous thread beyond description,
Lining what can not occur;
Its form formless,
Its image nothing,
Its name silence;
Follow it, it has no back,
Meet it, it has no face.