You have to love Psalms!  This is one of many that I have marked with repeated phrases.  The yellow and blue sections are great. The other highlighted sections are just similar thoughts. The shading was done by me for comparison.  

In my Bible, there is an introduction to this Psalm.  (This Psalm was copied from BibleGateway.com and is the New International Version.)  Apparently, at one time the introduction may have been the first verse.  It was written by David after the events of 1 Samuel 19: 11.  It would be fun to hear the actual tune that went with it when David wrote this song. Was it is up tempo or a slow mournful tune?

It is fair to say that David was not happy when he wrote it.  He was probably in his early twenties and not angry and fearful about what was being done to him!  Even in this very forceful wording, we find verse three, which is a shadow of the Pharisees and how they treated Jesus.  

New International Version (NIV) Holy Bible, New International Version®, NIV® Copyright ©1973, 1978, 1984, 2011 by Biblica, Inc.® Used by permission. All rights reserved worldwide.