During the Tang Dynasty's Longshuo era (661-663 AD), a monk named Sengjia arrived from the Western Regions to the Central Plains of the Great Tang. His virtue and learning were profound, and his words and actions were remarkably unusual, setting him apart from ordinary people. People respectfully called him Master Sengjia.
Once, the revered Buddhist master Sengjia was traveling through the Jianghuai region.
Someone asked him, "What is your surname?" He replied, "What surname." Another person asked, "What country are you from?" "What country," he answered.
The listeners took his words at face value, genuinely believing his surname was He and that he was a man from the state of He.
After Master Sangha's death, the famous Tang Dynasty writer and calligrapher Li Yong wrote an epitaph for his tomb, stating: "Master Sangha, whose secular surname was He, was a man of He Kingdom..."
After recording this story in his work *Night Talks from the Cold Studio*, the eminent Song Dynasty monk Huihong commented, "When Sengjia casually said his surname was He and he was from Heguo, Li Yong's epitaph turned it into fact—this is like a fool talking in his sleep!"
Later, the idiom "a fool's talk of dreams" came to describe ignorant people speaking absurd nonsense.
Source: *Lengzhai Night Talks*
Meaning of the Idiom: Later, the Chinese idiom "痴人说梦" came to describe ignorant people speaking absurd nonsense.