I Don't Know
The emperor, who was a devout Buddhist, invited a great Zen master to the Palace in order to ask him questions about Buddhism. "What is the highest truth of the holy Buddhist doctrine?" the emperor inquired.
"Vast emptiness... and not a trace of holiness," the master replied.
"If there is no holiness," the emperor said, "then who or what are you?"
"I do not know," the master replied.