Then he uttered another stanza:
“Imperturbable and serene the ideal man practises no virtue.
Self-possessed and dispassionate, he commits no sin.
Calm and silent, he gives up seeing and hearing.
Even and upright his mind abides nowhere.”
Having uttered this stanza, he sat reverently until the third watch of the night. Then he said abruptly to his disciples, “I am going now,” and in a sudden passed away. A peculiar fragrance pervaded his room, and a lunar rainbow appeared which seemed to join up earth and sky. The trees in the wood turned white, and birds and beasts cried mournfully.
...The Patriarch inherited the robe when he was 24, had his hair shaved (i.e. was ordained) at 39, and died (sat upright) at the age of 76. For thirty-seven years he preached for the benefit of all sentient beings. Forty-three of his disciples inherited the Dharma, and by his express consent, became his successors; while those who attained enlightenment and thereby got out of the rut of the ordinary man were too numerus to be calculated.
The Altar Sutra of Hui Neng (Chapter 10 – His Final Instructions)