David begins the prayer of Psalm 7:1 by saying, “LORD my God …”. In Hebrew this is literally, “Yahweh Elohe”. “Yahweh Elohim” is a familiar Old Testament expression for God: “Yahweh” is His personal name (often translated “LORD” but is the “I AM” personal, covenant name which God gave Moses and used throughout the Old Testament), and “Elohim” means “God.”
But it is significant that David does not use the term “Yahweh Elohim”, but “Yahweh Elohe” — this variation on the ending of “Elohim” means “MY God.” While ostensibly a small change, it has huge implications.