Idiom story of newborn calves who are not afraid of tigers

At the end of the Eastern Han Dynasty, Liu Bei seized Hanzhong from Cao Cao, proclaimed himself king, and ordered Guan Yu to take Xiangyang and invade Fancheng. Guan Yu led Liao Hua and Guan Ping to attack Xiangyang, while Cao Cao led Coss to resist. As a result, he was defeated and retreated to Fancheng. Cao Cao sent general Yu Jin as the general to levy south, with the brave general Pound as the pioneer, and led the troops to Fancheng for rescue.

Pound led the vanguard troops to Fancheng, and let the soldiers walk in front of the team carrying coffins to fight Guan Yu to the death. Pound bullied others and asked Guan Yu to beat him by name. Guan Yu went to war, and the two men fought for more than 100 rounds, regardless of the outcome, and the two armies each sounded their golden bells to retreat. When Guan Yu returned to the camp, he said to Guan Ping, "Pound is a brave general in Cao Ying because of his skillful knife cutting." Guan Ping said: "As the saying goes, newborn calves are not afraid of tigers." You can't despise him! The idiom "newborn calves are not afraid of tigers" here means that the brave general Pound has just been born and is unstoppable. Never underestimate your enemy.

Guan Yu felt that it was difficult to defeat Pound by force for a while, so he came up with a plan. At that time, the autumn rain continued, the Hanshui River soared, and Wei Jun Camp was stuck in a low-lying place. Guan Yu dug the Hanshui levee, flooded the seven armies, and escaped to the Forbidden City and Pound. When Yu Jin surrendered, Pound refused to give in until he knelt down. Guan Yu advised him to surrender, but Pound cursed instead. So Guan Yu ordered Pound to be killed.

This is the meaning and origin of newborn calves being afraid of tigers. In fact, in the story, we can see that this sentence has existed for a long time, otherwise it is impossible for Guan Ping to say "common cloud", but it is impossible to verify who said it before. Guan Ping is the first person with historical data, so this sentence is considered to be the source of this idiom.