Where did Ziming come from?
Lü Meng
"When Guan Yu went to attack Fancheng, he left behind many backup forces because he was afraid that I would seize the territories in his absence. I am often ill. Now, I request to return to Jianye under the guise of seeking medical treatment. When Guan Yu learns that I have left Jing Province, he will definitely withdraw the backup forces and move all out towards Xiangyang. When that happens, our troops will sail along the river, travelling day and night, and swiftly attack the weakly defended territories. We can thus conquer Nan Commandery and capture Guan Yu."[Sanguozhi 30]