《隋书·列传·卷十六》
前后使者数十人，摄图多不礼遇，独对长孙晟特别喜爱，每每与他一起游猎，留他在突厥到年底。
前后使人数十辈，摄图多不礼，见晟而独爱焉，每共游猎，留之竟岁。
There were dozens of envoys before and after him, but Shetu treated most of them with disrespect. Only Changsun Sheng was particularly favored by him. He often went hunting with him and kept him in the Turkic lands until the end of the year.