Xu Zao, a professor at the state academy of Wu Commandery, traced his ancestral home to Dongguan Commandery in Xuzhou. The Dongguan Xu Clan was a family of Confucian scholars, particularly accomplished in classical studies and phonology. Fifty years earlier, because of the Disaster of Yongjia, Xu Zao's father, Xu Chengzhi, and his fellow townsman Zang Kun had led over a thousand clansmen and neighbors south across the river and settled in Jingkou. Xu Zao had been born there. Studious from childhood, he had read widely in the classics and delved deeply into the Classic of Filial Piety, the Zhuangzi, and phonology. He also spoke pure Luoyang official speech. Yet because he did not belong to a great aristocratic house, the court had never entrusted him with important duties. He had first served as commissioner of waterways, then as a professor at the state academy of Wu Commandery. Many sons of Jiangzuo's aristocratic families studied the Luoyang-style Chant under him.
Xu Zao did not live within the city of Wu Commandery. Instead, he had built cottages beside Little Mirror Lake at the foot of Lion Mountain in the western outskirts, where he taught. There were more than ten thatched rooms, and he gave three lectures daily, each lasting half a double-hour: phonology and the Luoyang-style Chant in the morning, the Classic of Filial Piety in the afternoon, and the Zhuangzi at night. At other times, the students debated and challenged one another.
The students all lived in the city of Wu Commandery, arriving early and returning late. Xu Zao did not provide meals, so they brought their own noodle soup. This was tolerable in summer, but in winter, the food turned icy cold and was truly unpleasant to eat. Wealthy great families could never bear to let their sons suffer.