《明史·列传·卷二十四》
下台省府者，适宜设置铜柜收藏，以备查考，使其没有遗漏。 
下台省府者，宜各置铜柜藏之，以备稽考，俾无遗阙。 
For those who have stepped down from the provincial government, it is appropriate to establish a copper cabinet for collection, in order to prepare for future examination, so that there is no omission.