What happened: The king of Qin was always insatiable. The king of Zhao knew that he was just trying to cheat He Shibi, but he was afraid that the king of Qin would be too powerful to refuse directly to avoid war.
Just when he was embarrassed, Lin Xiangru stood up and claimed that he had a way-either to change back to the city or to bring He Shibi back to Zhao completely. In the state of Qin, the king of Qin was really only interested in Bi, and said nothing about giving up the city. And tried to forcibly seize the wall at a meeting.
Results: Lin Xiangru vowed. He grabbed He Shibi and prepared to hit the wall and threaten the king of Qin: either take the land as the wall and the city as the city; Otherwise, he will hit the wall, and the king of Qin will get nothing and be reviled for his treachery! Although the king of Qin loves beautiful jade, he is not fatuous. He refused to exchange land, so he had to let Lin Xiangru return to Zhao with He Shibi.
Historical background of the successful return of Yan Data to Zhao.
In 283 BC, the King of Zhao was awarded the Heshibi of the State of Chu. After hearing the news, Zhao Xiang, the king of Qin, wrote a letter to the prince of Zhao, expressing his willingness to exchange fifteen cities for Cui. The prince of Zhao consulted with General Lian Po and other ministers, but finally he didn't come to a conclusion, because if he gave gifts to the State of Qin, he was afraid that he wouldn't get the city. If he doesn't give Qin a gift, he is afraid of being attacked by him.
Just as this suspense was hanging in the balance, Miao Xian, the eunuch leader, came forward and offered an idea to the prince of Zhao, saying that his guest Lin Xiangru could go to the State of Qin. Wang Zhao asked, "How do you know?" Miao Xian said that he had committed a crime in the past and wanted to escape to Yan State. He was stopped by Lin Xiangru and asked him if he was interested. Finally, because he didn't leave Yan State, he got a chance to be forgiven by Zhao Wang. Therefore, he thinks that Lin Xiangru is wise and resourceful and can be entrusted with an important task.
The prince of Zhao summoned Lin Xiangru and asked Lin Xiangru if he wanted to exchange lottery for fifteen cities. Lin Xiangru analysis to the prince of Zhao, Zhao weak, have to change. But the prince of Zhao asked what to do if he gave both the king of Qin and Cui, but the king of Qin did not give him the city.
Lin Xiangru answered and said, in any case, Zhao will take risks, preferring Qin indefensible to Zhao indefensible. He also said that he was willing to take Bi into Qin. If the king of Qin reneged on his word and guaranteed that he would return to Zhao intact, the king of Zhao sent him to Qin.
Baidu Encyclopedia-Zhao returns intact