《宋史·列传·卷一百五十》
遇到晚上在经筵侍讲时，皇上赐座，留正认为不可，皇上不高兴。
会经筵晚讲赐坐，正执奏以为非，上不怿。
At night, during the classic lecture at the court, the emperor offered him a seat. Liu Zheng thought it was wrong, and the emperor was not happy.