During the Southern Dynasties, there was a man named Xu Ling. Legend has it that his mother, Zang, dreamed of a five-colored cloud transforming into a colorful phoenix that landed on her left shoulder; soon after waking, she gave birth to him. As a child, his family took him to visit the renowned monk Baozhi. Xu Ling was handsome, graceful, and had extraordinary eyes. Baozhi stroked his head and said, "This child is truly a stone qilin from heaven!" Another monk, Huiyun, often predicted he would achieve greatness early, comparing him to Confucius's prized disciple Yan Hui.
Xu Ling was indeed exceptionally gifted. By age eight, he could write essays, and by thirteen, he had already mastered the works of Zhuangzi and Laozi. As an adult, he read widely through historical records, citing extensively from them, and was not only highly learned but also possessed a sharp tongue, skilled in debate.
Xu Ling was a literary master of his time, widely regarded as the leading scholar of the age, with many imperial documents drafted by his hand. Every piece he wrote was eagerly imitated, copied, and recited by scholars and students alike. His style was ornate and graceful, breaking free from old conventions, and his works were fresh in form and concept. Alongside Yu Xin, he was celebrated as a peerless talent, their joint style known as the "Xu-Yu School."
Xu Ling was also a man of remarkable political talent. In 548 CE, during the second year of the Taiqing era, he was sent as an envoy to the Eastern Wei court. The Eastern Wei hosted a banquet in his honor. As the weather grew oppressively hot, the official Wei Shou mocked him, saying, "The north is never truly hot—this stifling heat today must have been brought here by our guest, Imperial Advisor Xu, all the way from the south." Without missing a beat, Xu Ling shot back, "Indeed, Wei once had no knowledge of proper rites and etiquette—it was only after Wang Su arrived that you people learned them. And now, I have been sent on this mission to teach you about the changing seasons of cold and heat." Xu Ling's sharp retort left Wei Shou utterly humiliated and red-faced with embarrassment. Source: *History of the Southern Dynasties*, "Biography of Xu Ling"
Later, "Heavenly Stone Unicorn" was used to describe having a son or praising someone else's son.
Source: *History of the Southern Dynasties*, "Biography of Xu Ling"
Meaning of the Idiom: Later, the Chinese idiom "天上石麟" came to describe having a son or praising someone else's son.