This image forms the frontispiece to Xu Shi zhenjiu daquan (Mr Xu's Great Compendium of Acupuncture and Moxibustion), first published in 1439. It is a graphic depiction of the traditional mode of transmission of medical knowledge. The figure seated behind the table is a master physician, and may represent the author Xu Feng himself. He is shown with acupuncture needles in his right hand, and the teaching text on the table in front of him bears the title Xu Shi zhenjiu (Mr Xu's acupuncture). The two young men standing in front of the table are his students or disciples. The one on the right also holds acupuncture needles, while the one on the left holds a medical text, suggesting a balance between theory and practice. The master is instructing them in the arts of acupuncture.