Melchizedek’s seeming appearance out of nowhere and almost equally quick disappearance in Genesis 14:17–20 prompted much speculation in the ancient world. Jewish writers were fascinated with the person and role of Melchizedek and wrote about him in many different texts. Of course, only Scripture gives an inspired look at Melchizedek, and the only other place in the Old Testament where we read of this king of Salem is Psalm 110, which also happens to be the most frequently referenced Old Testament text in the entire New Testament.
Psalm 110 is a remarkable prophetic passage, especially when we consider verse 4 and its use of Melchizedek. The psalm is written about a Davidic king who will be a priest. Yet this priest-king will not serve in the order of Levi but in the Melchizedekian order. For the old covenant believer, this pointed to a day when the Levitical priesthood would decrease and a Melchizedekian priesthood would increase, a point that the author of Hebrews expounds at length in chapter 7 of his letter.
Just as the first Melchizedek was a priest-king, this second Melchizedek will also be a priest-king, and most of Psalm 110 describes the nature of his righteous rule. First, it will be absolute. The imagery of the Davidic priest-king having his enemies as a footstool (v. 1) is based on events such as the one described in Joshua 10:24, where the ancient Israelites placed their feet on the necks of their defeated foes. Complete subjugation is pictured here—there will be no opponent whom the Davidic priestking will not vanquish.
The reign of the Davidic priest-king will also be eternal. God has sworn by Himself to put this son of David on the throne forever (Ps. 110:4). He will be unable to commit sin and thereby disqualify his righteous rule and intercession, and despite any appearances to the contrary, his throne will not finally be overturned. The Almighty Himself will fight with and on behalf of the Davidic priest-king, ensuring his ultimate success (vv. 5–7).
Today we see that Jesus Christ fulfills this psalm as the King of kings and High Priest in the order of Melchizedek. Not only is He David’s son, He is also David’s Lord (Luke 20:41–44), and He will rule alongside His Father forever (Rev. 11:15).