Jabir bin Abdullah (ra) narrated that Prophet (saw) while discussing about Dajjal said: And his donkey on which he will arrive, will have a span of 40 hands between his two ears. [Musnad Ahmad]
I want to know if this hadith is authentic or not (weak or fabricated etc.) ?
and
Is Musnad Ahmed an authentic source of hadiths as I heard that it contains many weak hadiths and has problems but I'm not sure.