Guishan is the thirty-seventh Ancestor, a direct descendant of Shakyamuni Buddha. He was a dharma heir of Baizhang, Zen Master Dazhi. Today buddha ancestors in the ten directions, even those who do not call themselves descendants of Guishan are all in fact his remote descendants.
One day while Guishan was lying down, Yangshan Huiji came to see him. Guishan turned to face the wall.
Yangshan said, "I am your student. Please don't be formal."
Guishan started to get up.
Yangshan rose to leave.
Guishan said, "Huiji."
Yangshan returned.
Guishan said, "Let me tell you about my dream."
Yangshan leaned forward to listen.
Guishan said simply, "Would you interpret my dream for me? I want to see how you do it."
In response, Yangshan brought a basin of water and a towel.
Guishan said, "Huiji and I have been sharing miracles. This is no small matter."
Xiangyan said, "I was next door and heard you."
Guishan said to him, "Why don't you try now?"
Xiangyan made a bowl of tea and brought it to him.
Guishan praised them, saying, "You two students surpass even Shariputra and Maudgalyayana with your miraculous activity!"
The Essential Dogen. Writings of the Great zen Master, s. 133.