Verse 23 is very important. In the NIV it reads this way....Above all else, guard your heart, for it is the wellspring of life. Also Matthew 12:34b says....Out of the abundance of the heart, the mouth speaketh. Meaning what is in your heart affects what comes out of your mouth. I've seen people who were very hard hearted. I've seen others who seemed to have a heart of gold. The first one was cruel and nasty, while the other one spoke kindly and always wanted to do all they could to be helpful.
What kind of person are you? What is your heart like? An easy way to tell is to listen to what comes out of your mouth. So, always remember to attend to God's word and above all...guard your heart.