《宋史·列传·卷九十五》
到这时，司马光面陈皇帝说： 我过去任并州通判时，上呈了三个奏章，希望陛下果断切实实行。 仁宗沉思了很久，说： 莫非是想选择宗室作为继承人吗？
至是，复面言： 臣昔通判并州，所上三章，愿陛下果断力行。 帝沉思久之，曰： 得非欲选宗室为继嗣者乎？
At this point, Sima Guang spoke to the emperor in person, saying: When I served as the deputy commissioner of Bingzhou, I submitted three memorials, hoping that Your Majesty would implement them resolutely and practically. Renzong pondered for a long time, saying: “Is this a matter of choosing an heir from the royal family?”