Commentary - Psalm 110:4

Bird's-eye view

Psalm 110:4 is the theological pivot of this entire coronation psalm, and arguably one of the most crucial verses in the Old Testament for understanding the person and work of Jesus Christ. Having established the Messiah as the enthroned King in verse 1, David, speaking by the Holy Spirit, now reveals the second, and equally essential, office of this same Lord: He is an eternal Priest. This is not just any priesthood; it is established by an unbreakable, unilateral oath from Yahweh Himself. And it is not of the common Levitical order, which was temporary and preparatory, but of a more ancient, mysterious, and superior order, that of Melchizedek. This verse, therefore, announces the union of the royal and priestly offices in one person, a reality that was impossible under the Mosaic covenant. The author of Hebrews unpacks this single verse over several chapters, showing it to be the foundation of the New Covenant and the basis for our eternal security in Christ.

In short, this verse tells us that the Messiah's work as our mediator is not an afterthought or a temporary arrangement. It is a central part of God's unchangeable plan, sworn into effect by God Himself, establishing a permanent and royal priesthood that completely eclipses the old one and provides the believer with a perfect, final, and eternal salvation.

Outline

Context In Psalm 110

Psalm 110 is a direct prophecy about the Messiah, a fact confirmed by Jesus Himself (Matt 22:41-46) and the apostle Peter (Acts 2:34-36). The psalm opens with Yahweh (the Father) speaking to David's "Lord" (the Son), inviting Him to sit at the place of ultimate power and authority, the right hand of the throne. The first three verses focus on His kingship, His rule, and His victorious conquest over His enemies. Then comes verse 4, which introduces a second, complementary reality: this mighty King is also a Priest. This is a stunning revelation. Under the Old Covenant, the offices of king (from the tribe of Judah) and priest (from the tribe of Levi) were kept strictly separate. For a king to usurp the priestly role was a grievous sin, as King Uzziah learned (2 Chron 26:16-21). This verse declares that the Messiah will uniquely combine both offices in His person. The remainder of the psalm (vv. 5-7) describes His work as a warrior-judge, which flows from His identity as both King and Priest.

Key Issues

The Oath That Grounds Our Salvation

We live in a world of broken promises, fine print, and shifting commitments. But the gospel is not built on such flimsy ground. The priesthood of Jesus Christ, which is the engine room of our salvation, is established on the most solid foundation possible: a sworn oath from Almighty God. God did not have to swear. His word alone is sufficient to call galaxies into existence. But, as the author of Hebrews explains, when God wanted to show the unchangeable character of His purpose, He guaranteed it with an oath (Heb 6:17). He did this for our sake, so that we who have fled for refuge might have strong encouragement to hold fast to the hope set before us. This oath is not a casual statement; it is the bedrock of our assurance. God has sworn that our Priest will never be replaced, His work will never be undone, and His office will never expire. He will not change His mind. The entire weight of God's immutable character stands behind the priesthood of His Son.

Verse by Verse Commentary

4 Yahweh has sworn and will not change His mind,

The verse opens with the ultimate authority. It is Yahweh, the covenant God of Israel, who is making this declaration. And He is not merely stating a fact; He is swearing an oath. In human courts, an oath is the most solemn form of speech, calling on a higher authority to witness one's truthfulness. But when God swears, there is no one higher to swear by, so He swears by Himself (Heb 6:13). This act invests the following declaration with the highest possible degree of solemnity and certainty. The phrase "and will not change His mind" reinforces this. The Hebrew word is often translated "repent," and it means that God will not have second thoughts, He will not reconsider, He will not revoke this appointment. The Aaronic priesthood was temporary and could be set aside, but this new priesthood is a permanent fixture in the divine economy. It is an unalterable decree.

“You are a priest forever

Here is the content of the oath. The "You" is the same person addressed in verse 1, David's Lord, the Messiah. He is appointed to the office of priest. A priest is a mediator. He stands between a holy God and sinful men. He represents men to God, offering sacrifices and prayers, and he represents God to men, communicating God's law and blessing. The Aaronic priests did this in a typological and temporary way. Their sacrifices had to be repeated daily and yearly, and they themselves would eventually die and need to be replaced. But this priest is different. His term is forever. His priesthood is not a temporary assignment; it is an eternal state of being. Because He conquered death, He lives forever, and therefore He holds His priesthood permanently (Heb 7:24). This means His saving work is never-ending. He is always interceding for His people. There will never be a moment when we are without a priest before the throne of God.

According to the order of Melchizedek.”

This final clause defines the nature of this eternal priesthood. It is not according to the order of Aaron, but that of Melchizedek. To understand this, we must go back to Genesis 14. Melchizedek appears briefly as the king of Salem (Jerusalem) and a "priest of God Most High." He blesses Abraham, the father of the Levitical tribe, and Abraham pays him tithes. This simple historical event reveals several crucial things, which the book of Hebrews brilliantly expounds. First, Melchizedek's priesthood is a royal priesthood; he is both king and priest. Second, his priesthood is superior to Aaron's, because Levi, figuratively in the loins of his great-grandfather Abraham, paid tithes to Melchizedek, and the lesser is always blessed by the greater (Heb 7:7). Third, his priesthood has no recorded beginning or end, no genealogy, making him a type of the eternal Son of God (Heb 7:3). So when God swears that the Messiah will be a priest after this order, He is declaring that Christ's priesthood will be royal, superior to the old system, and eternal in its nature.

Application

First, this verse is a fortress for Christian assurance. Is your salvation secure? It is as secure as the unbreakable oath of Almighty God. Your standing before God does not depend on your fluctuating feelings or your inconsistent performance. It depends on the permanent, eternal, and unchanging priesthood of Jesus Christ, who ever lives to make intercession for you. God has sworn He will not change His mind about your Priest. Therefore, you can have confidence.

Second, this verse radically simplifies our access to God. Under the old system, there were layers of mediation: priests, Levites, a temple, a veil, and a complex sacrificial code. But now, we have one Mediator, one High Priest, Jesus Christ. He is not only our Priest but also our King. He has both the compassion to represent us and the authority to save us. Because our King is our Priest, we can come boldly to the throne of grace, knowing it is a throne of grace precisely because our Priest is sitting on it as King.

Finally, this verse demands our ultimate allegiance. The world is full of would-be kings and self-appointed priests. But God has declared by an oath that there is only one true King-Priest. He alone has the right to rule our lives, and He alone has the power to forgive our sins. To reject Him is not to argue with a religious opinion; it is to defy a divine oath. Our only sane response is to bow to the King and flee to the Priest for mercy.