The treatise on Sleeping Gong ascribed to Chen Tuan is found the Marrow of the Red Phoenix,. It consists of a brief description of the basic practice, followed by twelve pictures of Sleeping Immortals, each of which is accompanied by a short poem. These poems cover the full panoply of Daoist imagery and metaphor relating to Daoist practices of inner cultivation and meditation including many direct and oblique allusions to the Dao De Jing (Tao Te Ching) of Lao Zi.

We present the ninth immortal: Zhang Xuan Xuan Firmly Fastens the Monkey and Horse.