《隋书·列传·卷十六》
皇上大喜，加授长孙晟开府，仍派他到突厥，亲自督杀大义公主。
上大喜，加授开府，仍遣入籓，莅杀大义公主。
The emperor was very happy, and promoted Zhangsun Sheng to Kaifu. He was sent to the Turks to personally supervise the execution of Princess Dayi.