《旧唐书·列传·卷二十二》
才到太阳偏西，诏命有才学的人，赐给清闲，围绕典籍高谈阔论，穿插作文咏诗及玄妙的谈论，到二更时分还不知疲倦，半夜还不去就寝。
才及日昃，命才学之士，赐以清闲，高谈典籍，杂以文咏，间以玄言，乙夜忘疲，中宵不寐。
It was not until the sun was about to set that he ordered learned men to be given leisure so that they could sit with him discussing important issues, writing poems and holding philosophical debates, and they did not feel tired until the second watch had begun, nor did they go to bed at midnight.