竭尽全力 — “To exert all one's strength or effort”

During the late Eastern Han Dynasty, there was a man named Yang Pei, courtesy name Kong Qu, who had served as the magistrate of Xinzheng. When Cao Cao passed through Xinzheng, his troops were short of provisions. Yang Pei assisted Cao Cao, earning his deep appreciation.

After Cao Cao became regent, Yang Pei was promoted to be the magistrate of Changshe. He feared no powerful figures and punished anyone who broke the law according to statutes, which earned Cao Cao's praise.

At that time, Cao Cao was away on a campaign and heard that public order in Ye City, the capital, was chaotic. He issued an edict to select a new magistrate for Ye City, with the criteria being someone possessing courage and capability like Yang Pei. After searching extensively and finding no suitable candidates, Yang Pei was promoted to be the magistrate of Ye City (then known as Jingzhao Yin).

Before Yang Pei officially took office, Cao Cao summoned him and asked how he intended to govern Ye. Yang Pei replied, "I will certainly exert all my heart and strength, vigorously promote laws and discipline, and ensure everyone abides by them." Cao Cao was greatly pleased by this and told his attendants, "Haven't you heard? This is truly a person to be respected."

Even before Yang Pei officially took up his post, some powerful landowners and imperial relatives, upon hearing that Yang Pei was coming to Ye City, hastened to admonish their own family members to behave themselves.