《北史·列传·卷四十》
九月下旬，后主启奏太后说 ：明天早晨我想与高俨一起出去打猎，早点出发，早点回来。 
九月下旬，帝启太后曰： 明旦欲与仁威出猎，须早早还。 
In the end of September, the last emperor reported to the Empress Dowager, saying: “Tomorrow morning I want to go out hunting with Gao Yan, leave early and come back early.”