《左传·哀公·哀公二十六年》
司城做了上卿，盟誓说： 三族共同掌握国政，不要互相残害！ 
司城为上卿，盟曰： 三族共政，无相害也。 
Si Cheng became premier minister and made them all take an oath, saying, "The three clans shall govern the state together and not harm one another."