《旧唐书·本纪·卷十一》
凡是臣下有事辞行或朝见，必须先到西宫跪拜，然后到朝堂朝见皇上。
凡人臣有事辞见，先临西宫，然后诣朝。
When any of the officials have a reason to take leave or to seek an audience, they must first kneel and bow in the Western Palace, and then go to the court hall to seek an audience with the emperor.