Li Shimin, later Emperor Taizong of the Tang Dynasty, was the second son of Li Yuan, Emperor Gaozu, and Empress Dou. He was born in the twelfth month of the eighteenth year of the Kaihuang era of the Sui Dynasty at a villa in Wugong. Legend has it that at the time of his birth, two dragons coiled outside the villa gates for three days before soaring away.
When Li Shimin was four years old, his father Li Yuan took him to Qizhou. There, a scholar sought an audience with Li Yuan, claiming he could read faces to predict fortune and misfortune, past and future.
After observing Li Yuan, he said, "You are a man of great fortune, and you have a noble son!" At that moment, Li Shimin approached Li Yuan. Upon seeing Li Shimin, the scholar immediately said, "With the bearing of a dragon and phoenix, and the countenance of a Son of Heaven, by the time he is nearly twenty, he will surely bring peace to the world and save the people."
Li Yuan, fearing that the scholar's words would leak and bring death upon him, was about to kill the scholar when the scholar suddenly vanished. Thus, adopting the meaning of "saving the world and pacifying the people," he named the future Emperor Taizong "Shimin."
Later, the idiom "Ji Shi An Min" came to describe saving the times and stabilizing the people.
Source: *Old Book of Tang*, "Annals of Emperor Taizong"
Meaning of the Idiom: Later, the Chinese idiom "济世安民" came to describe how saving the times and stabilizing the people.