The reason why Confucius "shocked" Zi Lu was that Zi Lu was not modest when talking about his ambitions and did not meet the requirements of governing the country with "propriety".

The words come from "The Analects of Confucius? Advanced Chapter? Zilu, Zeng Xi, Ran You, and Gong Xihua Sitting at the Sitting Room". The relevant passages are:

Zilu, Zeng Xi, Ran You , Gong Xihua sat down. Confucius said: "I think one day is long for you, so I don't think so. Ju Ze said: 'I don't know.' If I know you, how can I do it?"

Zi Lu led you and said to him. : "A country with a thousand chariots is taken between big countries, plus troops and troops, so it will be famine; if you do it, after three years, you can be brave and know the way."

The master sneered at it.

Confucius asked four disciples to discuss their ambitions. Zilu expressed his thoughts without hesitation or humility. Confucius laughed at him. Why are you laughing at him? There is a clear description in the article:

It said: "Master, why should I hesitate?"

It said: "If you serve the country with courtesy, you will not give in, so you will hesitate."

In response to Zeng Xi’s question, Teacher Confucius revealed the reason for ridiculing Zilu. The most important thing in governing a country is to pay attention to "propriety". To govern the country with propriety, Zilu said it in a loud tone and showed no humility at all. This could not be said to govern the country with propriety, so he ridiculed him.