Here David is speaking of the coming Messiah, who he calls Lord. He is a king who will both rule his people and conquer his enemies. He’s also a priest, like the priest-king Melchizedek. He sacrificed himself for his people, and represents them before God. New Testament quotations: Matt. 22:44; Mark 12:36; Luke 20:42, 43; Acts 2:34, 35; Heb.5:6; 7:17, 21