The Yu minister Gong Zhiqi advised against the deal, telling the duke, "There is a saying 'when the lips go, the teeth are cold.' The states of Yu and Guo are as interdependent as lips and teeth. When Guo is destroyed, Yu itself will soon be done for. On no account allow the Jin army passage on Yu roads!"
2. 虞國大臣宮之奇向虞公諫道：「俗話說：『唇亡齒寒』，虞、虢兩國蜃齒相依，虢國一亡，虞國也就完了，借道萬萬不可！」