A commentary is generally a verse-by-verse analysis and discussion of one or more books of the Bible, or possibly a portion of a book of the Bible. It generally includes an introductory section as well.
These commentaries have various call numbers. Search the library catalog for "Hermeneia" plus the name of the book of the Bible that you need.
Old Testament Library by Westminster John Knox
These commentaries have various call numbers. Search the library catalog for "Old Testament Library Westminster" plus the name of the book of the Bible that you need.
How to Search for Commentaries
To find commentaries on a specific book of the Bible, go the advanced search page of Pepperdine's library catalog: http://pepperdine.worldcat.org/advancedsearch. Choose "subject" from the drop-down menu and enter these search terms, substituting the name of the book you need:
Bible Commentaries Genesis
Pepperdine has both print and online commentaries.