"When Emperor Taizong began his glorious reign, ruling the people with enlightened wisdom, there was in the land of Da Qin a man of eminent virtue named Alopen. Guided by the azure clouds he bore the true scriptures, and watching the winds he braved hardship and danger. In the ninth year of Zhenguan (635) he arrived at Chang'an. The emperor sent his minister Duke Fang Xuanling with an honor guard to the western suburbs to receive him as a guest and bring him into the palace. The scriptures were translated in the imperial library, and the emperor inquired into the Way in his private apartments; deeply understanding its rightness and truth, he gave special orders for it to be taught and spread."
— Jingjing (Adam), priest of the Da Qin monastery
Source: Inscription of the Nestorian Stele (Stele of the Propagation of the Luminous Religion of Da Qin in China), AD 781