In 262 BC, the state of Qin attacked Han. Feng Ting, the general defending Shangdang, sent an envoy to Zhao, seeking an audience with King Xiaocheng of Zhao, saying:
“Our Korean forces are insufficient, and Shangdang is about to fall to Qin. However, our officials and people in Shangdang refuse to submit to Qin and would rather join Zhao. Our region has seventeen cities—we hope Your Majesty will accept us.”
King Xiaocheng of Zhao was delighted and summoned Lord Pingyuan, Zhao Bao, to seek his advice. Zhao Bao said:
“A sage views unearned gain as the greatest calamity. How can Your Majesty accept 17 cities without cause?” “This is due to my virtue—how can it be called unearned?” replied King Xiaocheng of Zhao.
Zhao Bao advised, "The state of Qin has been steadily encroaching on Han's territory and has long sought to annex Shangdang into its own domain. The reason Han offers Shangdang to us rather than to Qin is to shift the blame, aiming to turn Qin's aggression toward our state of Zhao. I urge Your Majesty not to fall for Han's scheme and bring disaster upon yourself."
King Xiaocheng of Zhao said with displeasure, "Even if we send a million troops to attack a city, we might not capture it in a year or more. Now, without spending a single soldier, we can obtain seventeen cities with ease—how could I simply give that up?"
After Zhao Bao departed, King Xiaocheng of Zhao summoned Lord Pingyuan, Zhao Sheng, and others to discuss the matter. Seduced by the immediate gains, Zhao Sheng urged the king, "Your Majesty, we must accept the Shangdang region." Persuaded, King Xiaocheng dispatched the great general Lian Po to lead troops and garrison Changping in Shangdang.
When Qin learned of this, it immediately turned its offensive toward Zhao, triggering the Battle of Changping. Zhao's commander, Zhao Kuo, was killed in action, and 400,000 of his soldiers were captured and buried alive. From that point on, Zhao's national strength never recovered.
Later, the idiom "shifting blame onto others" came to describe transferring misfortune to someone else.
Source: *Records of the Grand Historian*, "House of Zhao"
Meaning of the Idiom: Later, the Chinese idiom "嫁祸于人" came to describe transferring misfortune to someone else.