《管子·匡君大匡》
鲍叔说： 施伯的为人，聪敏然而伯事，您若及早去要，他害怕得罪齐国，一定不会杀的。 桓公说； 好。 
鲍叔曰： 夫施伯之为人也，敏而多畏。公若先反，恐注怨焉，必不杀也。 公曰： 诺。 
Bao Shu said: Shi Bo is an intelligent and humble person. If you go and ask him for Guan Zhong upfront, he is likely to spare him as he will be afraid of offending the State of Qi. Duke Huan said: Good.