The historical allusion is "Why can't we pick the melons on the imperial platform?" It is about the phenomenon of cannibalism caused by the struggle for imperial power, which comes from Li Xian's "The Tune of the Imperial Platform".
Original poem:
In the stage of planting melons, mature melons are separated.
Pick the melons well, and then pick them thin.
Three hesitations, the vines are gone.
Interpretation of vernacular Chinese:
Melons are planted under the yellow platform. In the mature season, many melons grow on vines. Picking a melon can make other melons grow better. Pick one more melon and you will see one less. If you pick three melons, there may be more melons, but if you pick all the melons, only vines are left.
Moral:
Li Xian here is actually a metaphor for melons, which means that if a mother takes her sons one by one like picking melons, only the withered "melons" will be left to her mother. And the person he said is Wu Zetian.
Extended data:
Prince Zhang Huai is a famous tragic crown prince in the history of China. As far as bloodline is concerned, he is the only son of two emperors in China history. Although his mother's eldest brother did not ascend to the throne, he was honored as "filial piety" after his death. His two younger brothers are Tang Zhongzong and Tang Ruizong, and his sister is Princess Taiping. She was in power for a period of time.
Li Xian lived in an out-and-out royal family, which doomed him to be involved in political struggle and unable to escape his tragic fate. As far as talent is concerned, Li Xian was the best in Wang Zizhong in the Tang Dynasty. In his twenties, he was able to summon outstanding imperial scholars to annotate the Book of the Later Han Dynasty, and his personal annotation was even called "Zhang Huai Annotation" by later generations, which was of great significance in literature and history.
As a prince, Li Xian supervised the country three times and won the praise of Emperor Gaozong and the support of ministers. It can be seen that this young prince is worthy of the heavy responsibility and a qualified successor to the empire. But at that time, his mother, Wuhou, was politically proud, and the mother and son were suspicious of each other and had a lot of bad feelings.
The marquis of Wu repeatedly blamed the prince with letters, while the palace circulated rumors that the prince was not marquis of Wu's own. In the end, the prince was not spared and became a victim of political struggle. In the first year of civilization (684), Emperor Gaozong died and Li Xian succeeded to the throne, but he was deposed by the marquis of Wu in just over a month, and the emperor Li Dan took charge of the state affairs.
Soon, General Qiu of Sargingowei was ordered to go to Bazhou to search his residence to prevent hidden dangers of rebellion. After Qiu arrived in Bazhou, he imprisoned him in another room and forced him to commit suicide. He is only 29 years old.
Baidu Encyclopedia-Huangtai Guaci