841 - Muhammad ibn 'Ali informed us, saying: Muhanna related to us, saying: I asked Ahmad about 'Umar ibn Sa'd, and he said: "It is not appropriate to narrate from him." I asked: "Who is he?" He replied: "The brother of 'Amir ibn Sa'd and the brother of Mus'ab ibn Sa'd." I asked: "Why?" He replied: "Because he is the leader of the armies and the one responsible for the bloodshed." I said to him: "It has reached me from Yahya ibn Sa'id that he said: 'Umar ibn Sa'd was not to be relied upon."