Possible Clues:

• O.T. book
• Bk. after Proverbs
• Book after Proverbs: Abbr.
• "All is vanity" Bible bk.
• Book after Prov.
• OT book after Proverbs
• O.T. book of teachings
• Bk. of the Bible
• Book following Prov.
• "Fear God, and keep His commandments" source: Abbr.