Psalm 9

I will praise You, O Lord, with my whole heart;
I will tell of all Your marvelous works...
The Lord is known by the judgment He executes;
The wicked is snared in the work of his own hands.

Meditation. Selah vv.1,16

Read chapter 9
There's no half-heartedness here, but David praising God with his WHOLE heart, his whole being.  What does it look like to praise God with our whole heart?  What causes for half-heartedness or even only a quarter of our hearts?
From this joy and praise of the Lord leads us to want to shout it on the rooftops of God, of what He's done and who He is.  It's our object of studying the scriptures and seeing that God's works are very marvelous.  Not only the ones in the past but also the ones to come!  We indeed pray for "Your kingdom come" but do we know what the Kingdom is, what we're praying for?  As we study and search we learn it's more than we can imagine and something we can't keep to ourselves.  What marvelous works of God do you desire to share with others?  Do you tell of what you've learned?  If not, why?
The Hebrew word for meditation is Higgaion, followed by Selah meaning pause.  The writer is telling the reader to literally meditate and pause on God, of who He is and what He's done and will do. So I tell you "HAGGION, SELAH."