David says: " Thou hast proved my heart. Thou has tried me and shalt find nothing." He was concerned that his footsteps would not slip. David fully expected to be heard by God. He wanted God to listen to him. Do you want God to listen when you pray? In our day, we better want Him to listen, because the world is wanting to close in on us. He better listen or we are sunk.
In the last verse I want to use the typical phrase 'right hand'. He says save by the right hand. In Isaiah 53, Jesus Christ is called the arm of God. It would have to be the right arm and thus the right hand. The whole chapter speaks of salvation from sin. It is mentioned six times. What David spoke about was already in the plan of God even before the foundation of the world. (I Peter 1:20) Do you know Him as your Savior?