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.
Psalm 55:16–21 includes a prayer for God to judge David's enemies, especially the traitor who was his former friend. David expresses supreme confidence that God will hear his prayer. Likewise, he is sure that those who ignore the Lord will be "humbled" and defeated.
David begins this song with a prayer for rescue, likely from his rebelling son, Absalom (2 Samuel 15:1–12). David is pained because of a close ally's betrayal; this would refer to Ahithophel, who sided with the rebels (2 Samuel 15:31). This situation creates intense fear. However, David is confident God will rescue him. He is fully assured that those who attack him will be humbled and judged by the Lord.