The legend depicted here concerns the most important of the three heroes of the founding of the Han dynasty, Zhang Liang (d. 187 BC). He was a native of the Han state, which was despoiled by Qin Shihuang when he unified China under the Qin dynasty. Bent on revenge, Zhang devoted his life and patrimony to the overthrow of the Qin, which he was finally instrumental in achieving, ensuring the enthronement of Liu Bang in 200 BC. While in hiding in Jiangsu province, he came across a learned old man who dropped his shoe off a bridge and begged Zhang Liang to go down and fetch it for him, which he immediately did. As a reward, the sage gave Zhang a book, telling him to read it and that in doing so, he would become the teacher of Princes.

The poem refers to the subject:
'Calling the young man by the bridge at midnight,
[To let him know that] unburnt books are still to be found.'