The study sheds light on the scientific status of Imam Al-Daraqutni, and the value of his book Al-Illal.It aims to collect the hadiths that cause the difference on Ismail bin Umayyah, to extract them, and to study the difference in them, with consideration of this difference, and to reveal the types of reason that came in some hadiths, and the presumptions of weighting between their chains of tran...