Explanation After Liu Xiu ascended the throne as Guangwu Emperor in the Eastern Han Dynasty, he sent general Feng Yi to lead the army to the Western Expedition to level the Red Eyebrow Army. Red eyebrow feign defeat, in the back of the stream to break Feng Jun. After Feng Yi's defeat to the camp, he called the scattered troops again, mixed people with the red eyebrow, and then attacked from inside and outside, breaking the red eyebrow at the bottom of the land. Afterwards, Liu Xiu, Emperor Guangwu of Han Dynasty, awarded him a letter, saying that Feng Yichu was defeated in Huixi, but he finally won in Mianchi. It can be said that you have lost something here first, and then you have gained something there. When you reward your merits, you can show your exploits.
Interpretation ① East corner: refers to the origin of the sun, that is, the morning, which means the beginning. ② Sang Yu: refers to the sunset, that is, the night, which means the end.
lost in the east corner, harvested mulberry and elm originally meant to lose something in one place and gain something in another. The latter metaphor has failed on one side, but achieved something on the other. It is often used.