孝經
Sun Quan once asked Yan Jun to recite something he memorised in his childhood. Yan Jun thus recited "The Scope and Meaning of the Treatise", the opening paragraph of the "Classic of Filial Piety". Zhang Zhao, who was also present, remarked: "Yan Jun is a mediocre scholar. I humbly seek permission to recite for Your Majesty." After Sun Quan approved, Zhang Zhao recited "The Service of the Ruler", another paragraph in the "Classic of Filial Piety". Sun Quan's other subjects agreed that Zhang Zhao had a good understanding of what he should recite in front of the emperor.