But You, O LORD, are a shield for me,
My glory and the One who lifts up my head.
I cried to the LORD with my voice,
And He heard me from His holy hill. Selah
David knew that The Lord was his shield, even though many people said that there was no help for him in God. The confidence David had in God, whom is a God of help and love, couldn't be shaken by others.
David needed a shield because he ws under attack from a ruthless and cuning enemy. David knew for a fact that God was his shield. This wasn't a prayer where he was asking God to fulfill this, oh no, this was a declaration of fact! A strong declaration which is: "You, O LORD, are a shield for me." This wasn't just something that he thought, it was FACT!.
The Lord God was much more than David's protection. God was the one who put David on higher ground, showing him glory while lifting his head. In David's circumstances was nothing glorious or nothing head-lifting, but in his God there was ! In God there was glory and head-lifting for David!
Glory is found in all sorts of things by man. Namely...
But David, he found his glory in The Lord! He found it in God! Not in the above mentioned things, but in God alone!
"Oh, my soul, hast thou made God thy glory? Others boast in their wealth, beauty, position, achievements: dost thou find in God what they find in these?"
Silent prayers are surely heard. Good men however find that even in secret, they tend to pray better aloud as opposed to praying whilst uttering no vocal sound.
Other people or individuals said that God wanted nothing to do with David, but David could say gloriously, "He heard me." The Lord God himself still held the ground of "the holy hill", and God would hear and help David from there.
David had so many things going against him, but he kept his faith in God, and that God would help him regardless of everything going on around him. David put his hope in God and God alone! Nothing else!