How to answer Xia Yuhe's next sentence on Daming Lake?

In the TV series Princess Zhu Huan, the summer by Daming Lake is a sentence to question the emperor, and the next sentence is also a poem. This poem is that a monarch should be like a rock and a concubine like a reed. Pucao is as tough as silk, and the rocks are not transferred.

In the play, Wei Zi is the daughter left by the emperor among the people. Emperor Wu of the Han Dynasty fell in love with his mother Xia when traveling incognito. Before leaving, the emperor promised Xia to come back to pick her up, but after returning to the palace, the emperor forgot about it. Xia became pregnant and gave birth shortly after Qin Shihuang left. At that time, it was immoral for women to have children out of wedlock. Xia is always pointed at, which has become her heart disease. Xia died of depression when she was a child.

Before he died, Xia gave him the keepsake that the emperor gave him, so that he could have time to meet the emperor in the Forbidden City. Later, Wei Zili went through all kinds of hardships and finally met the emperor and asked questions that had been buried in his heart for many years. The emperor was shocked, too, because Wei Zi looked exactly like the summer of that year.