《史记·七十列传·黥布列传》
因此，汉王严肃地派出使臣，进献不成熟的计策，希望大王认真地考虑。 
故汉王敬使使臣进愚计，原大王之留意也。 
Therefore, the King of Han sent his envoy to present his immature strategy, hoping that the King of Huainan would consider it carefully.