Once, Emperor Shun-tzung asked Ch'an Master Ju-man, "From where did the Buddha come? Where did he go? If we say the Buddha dwells in this world eternally, then where is the Buddha now?"
Master Ju-man answered, "The Buddha came from the eternal and returned to the eternal. His true nature is one with empty space. He dwells in a place where there is no-mind. The mindful merges with the mindless. The dwelling merges with the non-dwelling. He came and went away for the sake of all beings. The pure sea of true nature is his profound body that abides eternally. The wise should contemplate this carefully and not permit any doubts to arise!"
Emperor Shun-tzung was not convinced and said, "The Buddha was born in a palace and passed away between two sala [teak wood] trees. He taught for forty-nine years and said that he did not expound a word of Dharma. The mountains, the rivers and oceans the sun and moon, heaven and Earth --- all will cease to exist when the time comes. Who said there is no birth and no death? The wise should be able to grasp a clear understanding of this."
Then Master Ju-man explained, "The essence of the Buddha is non-being, and only the deluded will make distinctions. His true nature is one with empty space and will neither experience birth nor death. When the right conditions are present, the Buddha will be born. When the right conditions cease to exist, the Buddha will pass away. He teaches beings everywhere, just as the moon reflects on all water. He is neither permanent nor is he impermanent; he had neither an origin nor an extinction; he was neither born, nor did he ever die. When one sees the place of no-mind, then there is no Dharma to speak of."
Pleased with the response, Emperor Shun-tzung became more respectful toward the Master.
(Source: Hsing Yun's Ch'an Talk, Book 1)