《史记·三十世家·韩世家》
秦人司马庚三度往返于郢都，秦相甘茂和楚相昭鱼在商於相会，表面上扬言说要收回攻韩楚军的印信，其实双方好像是有什么密约。 
司马庚三反于郢，甘茂与昭鱼遇于商于，其言收玺，实类有约也。 
The Qin envoy Sima Geng traveled to Yingdu in Chu three times. The prime minister of Qin, Gan Mao, and the prime minister of Chu, Zhaoyu, met in Shangyu. They claimed to be taking back the seal of the army attacking Han and Chu, but it seemed as though they had some kind of secret accord.