It means: if we slack off now and don't pay close attention to this matter, we won't be able to annex the princes when they become strong and conclude a joint Covenant, even though they are as smart as the Yellow Emperor.

From: Biography of Historical Records Sima Qian Biography of Lisi in the Western Han Dynasty Seventy

Excerpt:

Today, princes serve Qin, such as counties. It is one of the times for a husband to take the power of Qin as the sage of Wang, which is enough to destroy the princes and become the inheritance of the emperor. Now, if you don't hurry up, the vassals will recover and get together. Although there are sages of the Yellow Emperor, they cannot be integrated.

Translation:

Now vassals obey the state of Qin just as counties obey the court. With the strength of Qin State and the wisdom of kings, just like sweeping away the dust on the stove, it is enough to destroy the princes, achieve the imperial industry and unify the world. This is a golden opportunity. If we slack off now and don't pay close attention to this matter, we can't annex the princes, even though they are as wise as the Yellow Emperor, until they become stronger and conclude an alliance.

Extended data

Biography of Lisi is a classical Chinese article written by Sima Qian, a historian of the Western Han Dynasty, which is included in Historical Records. This article is "Historical Records" Volume 87.

Biography of Lisi has a very broad social and political background, which actually involves the whole history of the rise and fall of Qin, and the rise and fall of Qin has a great relationship with Lisi. For example, Li Si remonstrated against the expulsion of guests, summed up the historical experience of Qin State, and actually put forward the major policy of employing people regardless of the country. Qin Shihuang adopted this policy, "more than 20 years, unified with the world."

The main feature of this biography in literature is that it is good at psychological description. For example, at the beginning of this biography, the author chose a typical event in Reese's early life, that is, he saw a mouse in the toilet and a mouse in the granary, both of which were mice, but in different circumstances. From this, he realized that people, like mice, are both promising and worthless, which is determined by their environment. In other words, the nature that climbs to a high position is promising, and the nature that falls to a lower level is incompetent, which shows that Reese is dumping.