During the reign of Empress Wu Zetian of the Tang Dynasty, many renowned ministers emerged, including the two famous chancellors Yao Chong and Lu Huaishen.
Yao Chong was renowned for his sharp efficiency and impeccable judgment, while Lu Huaishen was admired for his willingness to listen to all opinions and his incorruptible dedication to public service.
Yao Chong was an official personally promoted by Empress Wu Zetian. When the Khitan forces overran several prefectures in Hebei, military affairs became overwhelming in both volume and complexity, yet Yao Chong handled everything with such order that even mountains of documents were processed within days, earning him the empress's deep respect.
In the fourth year of the Kaiyuan era, a massive locust plague struck Shandong. Local officials, following old customs, led the people in burning incense and praying at altars, hoping Heaven would take pity and recall the insects. But Chancellor Yao Chong urgently issued an official directive, pointing out to the officials: "Locusts fear people; people need not fear locusts. They devour crops, and farmers will spare no effort to protect their fields. Like all insects, locusts fly toward fire at night. Light bonfires at the field edges, dig pits beside them, and burn and bury them together—this will wipe them out completely."
Lu Huaishen disagreed, saying to Yao Chong, "The court officials all say locusts are a natural disaster, not to be eliminated by human effort. Moreover, killing too many insects harms harmony and provokes heaven's wrath. After the plague, other terrible disasters may follow. This matter requires caution."
Yao Chong retorted, "If locusts should not be killed, should the people of Shandong be left to starve to death? If exterminating locusts brings other disasters, I, Yao Chong, am willing to bear the court's severe punishment alone!"
Ni Ruoshui, the governor of Bianzhou, stubbornly insisted that natural disasters could only be dispelled through cultivating virtue, arguing that killing locusts was less effective than reducing punishments and taxes in aligning with the great principle of virtue. He flatly refused to accept Yao Chong's locust-eradication plan.
Yao Chong was furious and ordered again, "After the locust plague, the people have no food—what kind of virtue is this? If cultivating virtue could prevent locusts, then the locust plague in Bianzhou is especially severe—does the governor have virtue or not?"
Ni Ruoshui had no choice but to carry out the order to burn and bury the locusts, capturing 140,000 shi of them and casting them into the Bian River, where they drifted for over a hundred li.
Yao Chong acted with the swiftness of a thunderbolt, and the locust plague soon began to subside
From then on, Lu Huaishen knew he was far inferior to Yao Chong in handling practical affairs, so whenever major local projects or official appointments and dismissals arose, he deferred entirely to Yao Chong's sole judgment. Witty Tang-dynasty people nicknamed Lu Huaishen the "Dining Companion Chancellor."
Later generations used the term "figurehead chancellor" to mock high-ranking officials who hold positions without doing real work.
Source: *Old Book of Tang*, "Biography of Lu Huaishen"
Meaning of the Idiom: Later, the Chinese idiom "伴食宰相" came to describe how high-ranking officials hold positions without doing real work.