孝經
At the age of twenty-two, he returned to the Confucian classics and deepened his understanding, studying at the Yixueyuan 義學院 Confucian Academy in Suizhou. His later writings reveal a detailed familiarity with the "Analects", the "Classic of Filial Piety", and the "Book of Rites", as well as historical texts and Daoist classics such as the works of Laozi.