What idioms and allusions are there between Chu and Qin?

Go to the Qin Dynasty and the Qin Dynasty.

Dynasty is an idiom in China, and its pinyin is zhāo qín mù chǔ, which means that during the Warring States period, two vassal states in Qin Chu were opposed and often fought wars. In order to ensure their own interests and security, some vassal States sometimes tended to Qin and sometimes to Chu.

The story of "morning and evening" recorded in the history books is at the Zijingguan at the junction of Henan and Shaanxi-"About 5 kilometers up the Danjiang River, you arrive at a place called Moon Bay. At the junction of Henan and Shaanxi, there is a gap between the two mountains. Outside the customs, it is eight hundred miles of Qinchuan; Inside Shanhaiguan Pass, it is the open Central Plains. The roaring Danjiang River and the narrow ancient road are isomorphic here, building a pass of "one person guarding it, ten thousand people are not allowed". This pass is the "pass" of Jingziguan. Jingziguan got its name from this. This pass is the second legend of Jingziguan. There is a dangerous pass here. Only green mountains and green waters can tell clearly how many wars have taken place since ancient times. According to historical records, the influential war in the early period of Jingziguan should be the "Danyang War" between Qin Chu. During the Warring States Period, Qin and Chu fought frequently. At that time, Jingziguan was the boundary between Qin State and Chu State, part of which belonged to Qin State and part to Danyang County of Chu State. In 3 12 BC, the "Danyang War" broke out between Qin and Chu, and Qin took advantage of the dangerous terrain of Jingziguan to defeat Chu in one fell swoop. After the victory of Qin, Jing Ziguan was all incorporated into the territory of Qin. After that, Qin Chu and China were repaired, and the State of Qin gave this place to the State of Chu. There is an idiom called "Sooner or later", which is interpreted in modern Chinese dictionaries as: one tends to Qin and the other relies on Chu, meaning that people are capricious. Few people know that the origin of this allusion is in Jingziguan.