615 Wali Allah al-Dihlawi says...
615 Wali Allah al-Dihlawi says: “The Musnad books brought together the sahih, hasan (good), da’if (weak), well-known, odd, eccentric, disapproved, mistaken and right, thabit and maqlub (reversed) traditions. Besides, they could never gain that fame among the ulama’, though they be no more deemed fully disapproved, nor their veracity or weakness be fully investigated by the traditionists.
And among them are some that no grammarian could use because of their oddity, no faqih could comply with the madhahib of the salaf (predecessors), no traditionist could manifest their dubiety, and no historian could refer to names of their rijal.” 616 Al-Nawawi, in his Taqrib, when discussing the hadith books and their ranks, said: Concerning Musnad Ahmad ibn Hanbal and Musnad Abi Dawud al-Tayalisi and other Musnads, they can never be counted to occupy the same position of the five books and their likes, in respect of argumentation and reliance on whatever cited in them.
617 Comments on Musnad Ahmad: The statements mentioned before were comments on ranks of Musnad books in general among hadith books, that could be considered as unanimously agreed among traditionists. In regard of Musnad Ahmad in particular, I quote herewith some comments of leaders of hadith on it, initiating with utterance of Imam of Hanbalis after Ahmad: Ibn Taymiyyah.
After quoting these sayings, we are not to blame if this would enrage any of those claiming to be rijal of hadith nowadays, as truth should be followed. And I have never brought out this book but only for the purpose of pleasing the truth (haqq) alone, and if any one be enraged, his anger should be with truth not with us. About Abu Nu’aym, Ibn Taymiyyah said: He had reported many traditions that were deemed weak or rather fabricated, according to concurrence of ulama’.
And though he was a trustworthy memorizer, known of being prolific in narrating the hadith, and of extensive riwayah, but he used to — like other similar narrators – narrate whatever contained in the chapter (bab) for being acquainted with that, although he could not use all of it, except some portion, in argumentation .
This while the authors of Musannafs were not reporting from those known to be falsifiers, like Malik and Shu’bah and Ahmad ibn Hanbal, who were never reporting from any narrator they could never trust, nor relating any hadith from that known to be one of those who were deliberately falsifying the hadith.