During the reign of Emperor Wen of the Han Dynasty, tensions between Han China and the nomadic Xiongnu to the north were at a breaking point. The Xiongnu frequently raided the border, aiming to seize the fertile lands south of the Yinshan Mountains and force a crossing of the Yellow River into the Fen or Yellow River valleys. To counter this threat from the northwest, Emperor Wen made serious military preparations, appointing three generals—the Imperial Secretary Liu Li, Marquis Zhu Zi Xu Li, and the Governor of Henei Commandery Zhou Yafu—to lead troops stationed at Bashang, Jimen, and Xiliu respectively.
With the Han dynasty's military defenses in place, the people's anxiety eased somewhat, but Emperor Wen of Han remained uneasy. He decided to personally visit the three key military outposts to comfort the troops, inspect the camps, and assess their defensive strength.
When Emperor Wen of Han first arrived at Bashang and Jimen, he found the camp gates wide open with no guards in sight, his imperial chariot rolling straight through without any challenge, the soldiers lax and undisciplined, showing no signs of battle readiness. Troubled, the emperor watched as the generals and officers came out on horseback to greet him in formation, each vying to boast, "The Xiongnu are nothing to worry about!" and "We'll crush them with ease!" As he left Bashang and Jimen, Emperor Wen felt a heavy weight in his heart, sensing these troops were unreliable—could they truly fend off a Xiongnu invasion?
Then Emperor Wen of Han drove his carriage to the Willow Camp. His advance honor guard arrived at the camp gate but was blocked by sentries who refused to let them enter.
The commanding officer told the guard, "The emperor himself is coming to reward the troops, and his carriage will arrive soon. Why don't you let us through quickly!" The guard replied, "In the camp, we only follow General Zhou's orders. Without the general's command, no one is allowed to enter the camp."
A short while later, Emperor Wen of Han's chariot arrived, only to be stopped again outside the camp gate. The emperor had no choice but to send an envoy bearing the imperial tally to Zhou Yafu, informing him that the emperor himself had come to personally inspect and comfort the troops. Zhou Yafu then issued the order to open the camp gates wide. As the guards opened the gates on command, they cautioned, "General Zhou has decreed that no chariots or horses may race within the camp; violators will be executed."
The emperor nodded in approval and ordered the chariot to be reined in, proceeding slowly. Upon reaching the camp, Emperor Wen dismounted, and Zhou Yafu, holding his weapon, came forward to salute. Zhou Yafu said to the emperor, "I am in armor and cannot perform a full bow; please allow me to salute according to military protocol." He then clasped his hands in a formal salute.
Emperor Wen was deeply impressed by the discipline at Xiliu Camp, where soldiers and officers alike were clad in iron armor, weapons in hand, drilling in formation as if ready for battle. After completing his inspection, the emperor departed without delay.
As they exited the camp, the accompanying officials felt Zhou Yafu had gone too far, showing such strict caution even toward the emperor's carriage. Emperor Wen of Han, however, sighed and said, "Zhou Yafu is a true general! The troops at the other two camps were mere children playing games—how could they have any fighting spirit? But this army Zhou Yafu commands—who could defeat it? Only an army like this can win battles!"
Later, people used the idiom "treating it like child's play" to refer to matters handled with extreme carelessness and a lack of seriousness.
Source: *Records of the Grand Historian*, "Biography of the Marquis of Jiang and Zhou Bo"
Meaning of the Idiom: Later, the Chinese idiom "视同儿戏" came to describe how matters handled with extreme carelessness and a lack of seriousness.