What does Psalm 55:19 mean?
David's confidence in God to answer his prayer was high, and so was his concept of God. Despite intense danger (Psalm 55:2–5), he is assured that the Lord will defeat his enemies (Psalm 55:16–18). David had a right to sit on the throne of Israel (2 Samuel 7:9, 11), but God has been the unchallenged King for all time (Deuteronomy 33:27). Those who fail to give God proper respect and reverence—those who do not "fear" him (Proverbs 1:7)—will refuse to submit to truth. They will suffer the consequences of that stubbornness (Proverbs 14:27).Before the dawn of human history Lucifer sinned by coveting God's throne (Isaiah 14:13), but God humbled him. He told Lucifer, "But you are brought down to Sheol, to the far reaches of the pit" (Isaiah 14:15). When King Uzziah died, Isaiah entered the temple and caught a vision of God. He saw Him "sitting upon a throne, high and lifted up" (Isaiah 6:1). The apostle John, too, received a vision of God. He writes: "At once I was in the Spirit, and behold, a throne stood in heaven, with one seated on the throne" (Revelation 4:2).
This is verse is split by the Hebrew term selah. This most likely implies a pause, or a musical interlude. David seems to be calling for a moment of reflection about God's eternal nature, before continuing to explain why his enemies are doomed to failure.