During one of his Dharma talks, Huineng told the assembly, “There is something without name or description. It doesn’t have eyes or ears, head or tail, neither front nor back, inside or outside. It’s neither cause nor effect. What is it?”
When none of the older monks replied, Heze Shenhui said, “It’s the Buddha-nature, the source of all things.”
“If it has neither name nor description,” Huineng retorted, “how can you call it the Buddha-nature?”
“Buddha-nature has neither name nor description, but because my Master asked what it was, name and description are used. However, even named and described, it remains without name or description.”
Huineng struck the boy and dismissed the assembly. Later, however, Huineng sent for Shenhui and asked, “Today I struck you. Was it you or Buddha-nature which felt the blow?” When confronted with this question, Shenhui came to awakening. After this he served as Huineng’s attendant until the Patriarch’s death.
[Heze Shenhui – Zen Master’s of China :79-81]