In Wei, Zheng An’ping hid the fugitive Fan Ju under a new name. When the Qin envoy Wang Ji asked whether Wei had a worthy man to take west, Zheng An’ping brought Fan Ju to him at night. Wang Ji carried Fan Ju into Qin, where he rose to chief minister. At Fan Ju’s urging, the king made Wang Ji governor of Hedong and also took on Zheng An’ping, as a general.
Later, Zheng An’ping was surrounded by Zhao and surrendered with 20,000 men. Fan Ju sat on straw and asked to be punished. The Records of the Grand Historian explains: “Under the law of Qin, when a man recommends someone and the one recommended proves bad, each is punished for that crime.” Fan Ju’s crime called for the seizure of three sets of his kin.
King Zhaoxiang, afraid of hurting his chief minister’s feelings, ordered that anyone who spoke of Zheng An’ping would be punished for the same crime.