Around the year 950, the emperor received an anonymous poem that made him change his mind about removing an ancient plum tree that had recently died: "Since my lord commands, what can I do but obey; but the nightingales, when they ask about their nests-- whatever can I tell them?" The character for "nightingale" is perched upon the branch; amazingly, it (and the other characters) consists of clay, inserted into the cut-out wall of the vessel.