David is full of joy because the Lord has heard his prayer. The one with whom he has the closest relationship turned his ear to him. His heart trusted in the Lord. He was helped. David was weak. So the Lord was his strength. David was vulnerable. So the Lord was his shield protector. David was trapped. So the Lord was his salvation fortress. David praised the Lord in song.
More times than I remember I was in similar circumstances as David; weak, vulnerable, and trapped. Here I am for the Lord is my strength, shield protector, and salvation fortress. Praise be to the LORD, for he has heard my cry for mercy. I will give thanks to him in song. If I am not heard by others because my sound is not heard; then am I singing? Do not be silent.
A good shepherd cares for the sheep. When the sheep cannot continue their walk he carries them. He carries his lambs forever for we are weak, vulnerable, and trapped. We are blessed. We are saved. The Lord Jesus is our good shepherd.