This psalm of David points to the coming Messiah who would be both priest and king. Jesus quoted from this psalm saying that David spoke “in the Spirit” (Matt. 22:43), for truly David’s words were Spirit inspired.
Since the offices of priest and king were separated in Israel, David had to look back to Melchizedek, whose name means “king of righteousness,” to find such a one. Melchizedek appears suddenly on the pages of the book of Genesis as the King of “Salem” (“shalom,” meaning “peace”) and “Priest of the God Most High” (Gen. 14:17). He blessed Abraham, who paid him a tithe, and then he is not heard from again until the Spirit brought him to David’s mind.
Who is this that would come in the “order of Melchizedek” that the Lord would swear and “not relent” to establish His eternal priesthood? It is Jesus the Christ. For Christ “arises in the likeness of Melchizedek” (Heb. 7:15) becoming both our King and our eternal and Great High Priest!