diff --git a/book/05-distributed-git/sections/contributing.asc b/book/05-distributed-git/sections/contributing.asc
index 2019ff3eb..f30799000 100644
--- a/book/05-distributed-git/sections/contributing.asc
+++ b/book/05-distributed-git/sections/contributing.asc
@@ -143,7 +143,12 @@ To jessica@githost:simplegit.git
    1edee6b..fbff5bc  master -> master
 ----
 
-John tries to push his change up, too:
+The last line of the output above shows a useful return message from the push operation.
+The basic format is `<oldref>..<newref> fromref \-> toref`, where `oldref` means the old reference, `newref` means the new reference, `fromref` is the name of the local reference being pushed, and `toref` is the name of the remote reference being updated.
+You'll see similar output like this below in the discussions, so having a basic idea of the meaning will help in understanding the various states of the repositories.
+More details are available in the documentation for https://git-scm.com/docs/git-push[git-push].
+
+Continuing with the example, John tries to push his change up, too:
 
 [source,console]
 ----
diff --git a/book/10-git-internals/sections/objects.asc b/book/10-git-internals/sections/objects.asc
index 8c7e5b373..a063d616c 100644
--- a/book/10-git-internals/sections/objects.asc
+++ b/book/10-git-internals/sections/objects.asc
@@ -188,9 +188,8 @@ You'll now create a new tree with the second version of `test.txt` and a new fil
 [source,console]
 ----
 $ echo 'new file' > new.txt
-$ git update-index --cacheinfo 100644 \
+$ git update-index --add --cacheinfo 100644 \
   1f7a7a472abf3dd9643fd615f6da379c4acb3e3a test.txt
-$ git update-index test.txt
 $ git update-index --add new.txt
 ----