From the words of Ahmed bin Hanbal regarding the reasons for hadith and knowledge of men

Translation

This book is a collection of reasons and questions collected by Ahmad ibn Hanbal. It contains various issues about men and narrators, and it also includes some footnotes and comments on these questions. The book seems to focus on determining the credibility of narrators and narratives, and also includes some information about the lives and works of some narrators. This book is considered an important source for historical and heritage studies in Islam, and is considered part of the important Islamic heritage.