Zhang Jiuling
During the middle of Emperor Xuanzong's "Kāiyuán" era (713-741), Emperor Xuanzong was interested in the classic texts, and often had scholars explain the texts to him. Originally, this was done by the officials Chǔ Wúliàng () and Yuán Xíngchōng (). After Chu died in 719 and Yuan died in 729, Emperor Xuanzong engaged Chen Xilie and Féng Cháoyǐn () to frequently explain the "Tao Te Ching" and the "I Ching" to him. Chen was initially promoted to be "Mìshū Shàojiān" (), the deputy head of the Palace Library, and also succeeded Zhang Jiuling in heading the imperial institute Jíxián Institute (). Whenever Emperor Xuanzong was writing something of importance, Chen would assist him in drafting the language. In 742, when the official Tián Tóngxiù () reported seeing an appearance of Laozi above Dānfèng Gate (), Chen was one of the officials who submitted a statement flattering Emperor Xuanzong for the holiness of his reign.