《宋史·列传·卷二百零三》
于是司马光将刘恕召为局僚，凡遇到纷错难治的史事，皆委其考证。
即召为局僚，遇史事纷错难治者，辄以诿恕。
Sima Guang then appointed Liu Shu to the bureau, and any historical events that were complex and difficult to sort out were assigned to him for investigation.