Al -Kafi in the jurisprudence of Imam Ahmad bin Hanbal is a book of jurisprudence, written by Al -Hafiz Ibn Qudamah, and it is a book on the doctrine of Imam Ahmad, in which his author mentions most of the narrations on the authority of Imam Ahmad bin Hanbal and the evidence of every novel, and the conclusion of every narration. Al -Hafiz Ibn Qudamah said in the introduction to his sufficient book