Idiom story: In 227 BC, Qin defeated Zhao and approached Yan. Yan Wangdan asked Jing Ke to assassinate the king of Qin. Jing Ke took the head of Fan, the enemy of the King of Qin, and a map of Du Kang. Taizi Dan sent him to Yishui, and when he saw the ceremony, he struck the floor and sang for Jing Ke: "The wind is rustling and the water is cold, and the strong man is gone forever." After the generous feather sound, all the people were surprised and crowned.