An interpreter does not need every reported detail about every incident connected with a verse. The first requirement is acquaintance with the accounts whose particular features materially affect what the verse means.
If a verse alludes to an expedition or incident whose intended lesson depends on its circumstances, those relevant circumstances should be known. This is a real need for historical explanation.
The principle is selective necessity: investigate historical details when they determine the meaning; do not burden an otherwise clear general statement with irrelevant narrative elaboration.