This ancient prose means that Yu Xun gave it to Cao Cao in the battle of Guandu.

Yuan Shao has assembled all his troops in Guandu to fight you (Cao Cao). You (Cao Cao) use the weakest force to resist the strongest enemy. If you can't subdue the other side, you will be attacked by the other side. This is a moment concerning the fate of the world. Although Yuan Shao has many soldiers, he is not good at fighting. And you (Cao Cao) wise SHEN WOO, how can there be impossible things? Although there are not many rations now, it is more difficult than Liu Bang's confrontation with Xiang Yu in Xingyang and Gaoping. You (Cao Cao) should hold your ground and hold your throat, so that Yuan Shao's army can't move forward, and wait until Yuan Shao's army is exhausted before attacking. This is an opportunity to win by coup, and you must not miss it. I hope you (Cao Cao) will think it over.