Feng Zizhen (J. Fû Shishin, c. 1257-1327) was a writer and poet of the Yuan dynasty (1279-1367) from the You County in Hunan. Writing under the name of Haisu (J. Kaizoku), he excelled in both prose and poetry. Late in his life he became a Chan (J. Zen) practitioner, and he was acquainted with many prominent Chan monks, including Zhongfeng Mingben (J. Chûhô Myôhon, 1263-1323) and Gulin Qingmou (J. Kurin Seimo, 1262-1329). It seems that he also taught many Japanese monks.
This calligraphic work, written by Feng Zizhen himself, is made up of three poems he composed for the Japanese monk Muin Genkai. The format of the poems is seven characters per line (J. shichigon zekku). Despite the fact that some lines appear to have fewer than seven characters, the total number of characters in each poem is in fact divisible by seven.
Muin Genkai was from Buzen Province (present-day northern Kyûshû). He traveled to China in 1308 (Enkyô 1) and studied under Zhongfeng Mingben, before returning to Japan in 1326 (Karyaku 1) to become the head monk of Kennin-ji Temple in Kyoto. Feng Zizhen also wrote other pieces of calligraphy for Muin Genkai, which indicates that he must have had a high regard for the Japanese monk.