From the man git-stash page:
The modifications stashed away by this command can be listed with git stash list, inspected with git stash show
show [<stash>]
Show the changes recorded in the stash as a diff between the stashed state and
its original parent. When no <stash> is given, shows the latest one. By default,
the command shows the diffstat, but it will accept any format known to git diff
(e.g., git stash show -p stash@{1} to view the second most recent stash in patch
form).
To list the stashed modifications
git stash list
To show files changed in the last stash
git stash show
So, to view the content of the most recent stash, run
git stash show -p
To view the content of an arbitrary stash, run something like
git stash show -p stash@{1}