During the reign of Emperor Jiajing of the Ming Dynasty, the treacherous prime minister Yan Song monopolized power, filling the court with his cronies—"guests filled the official ranks, relatives all wore purple and scarlet." These people colluded from top to bottom, committing every kind of evil that harmed the nation and the people.
Some upright officials, unwilling to see the state ruined, risked their careers and lives by submitting memorials to the emperor, impeaching Yan Song for his crimes. Among them was Dong Chuance from Huating County, Songjiang Prefecture, then serving as a secretary in the Ministry of Justice. In the thirty-seventh year of the Jiajing reign, he submitted an impeachment memorial, stating, "Yan Song has accumulated evil and misled the state—does Your Majesty not see through his treachery clearly? ... As long as Yan Song holds power for one day, the empire suffers one day of harm."
The dim-witted Emperor Jiajing still refused to heed loyal counsel, throwing Dong Chuance into prison and later exiling him to distant Nanning.
" 'Dong' means to see clearly and deeply; 'zhu' means to illuminate, which can be extended to perceive. The idiom 'Dong Zhu Qi Jian' describes a person with keen observation, able to thoroughly see through others' schemes and tricks."
Source: *History of Ming*, "Biography of Dong Qice"
Meaning of the Idiom: Later, the Chinese idiom "洞烛其奸" came to describe a person with keen observation, able to thoroughly see through others' schemes and tricks.