Ellis Davidson: Valhalla in the grave
There [in Valhalla] is said to be a hall with many doors, filled with shields and mailcoats and haunted by the wolf and the eagle. It seems indeed to be a kind of riddling account of the field of battle, where the wolf and the eagle are busy and where the doors of death are opened for many.
H.R. Ellis Davidson in Scandinavian Mythology (1969), p. 42.