Ruiyan asked Yantou, “What is the fundamental constant principle?”
Yantou said, “Moving.”
Ruiyan said, “When moving, what then?”
Yantou said, “You don’t see the fundamental constant principle.”
Ruiyan stood there thinking.
Yantou said, “If you agree, you are not yet free of sense and matter; if you don’t agree, you’ll be forever sunk in birth or death.” (The Book of Serenity)

Poor Ruiyan! What can he do? Do you see where he made the mistake?