Psalm 110 Rests on an Oath
Why the New Testament Keeps Quoting One Psalm
Depending on who is counting, and whether clear echoes are counted alongside direct quotations, the New Testament reaches for Psalm 110 somewhere between twenty-five and thirty-three times. No other chapter in the Old Testament gets pulled into the New that often, and the first person to quote it there was Jesus, standing in the temple courts a few days before He died.
He had been fielding questions, each one built to trap Him. When the Pharisees had run out, He asked one of His own. Whose son is the Christ? They answered without hesitating: David's. So He quoted David back to them.
The LORD said to my Lord, "Sit at My right hand, till I make Your enemies Your footstool." (Psalm 110:1)
If David calls Him Lord, Jesus asked, how is He David's son? Matthew records the result in one line: no one was able to answer Him a word. The best-trained men in Israel knew the psalm. They simply hadn't reckoned with what it described. A King whom David himself bows to. A King seated, not standing. And three verses later, something no king in Israel's history had been allowed to be.
The Verse Hebrews Reaches For
Verse 1 is the line the rest of the New Testament reaches for. Matthew, Mark, and Luke record Jesus quoting it, Peter preaches it at Pentecost, Paul builds on it in Corinth and Ephesus, and the risen Christ is described as seated at the right hand from Romans through 1 Peter. The book of Hebrews does something different. It goes to verse 4, and it goes there five times in three chapters.
The LORD has sworn and will not relent, "You are a priest forever according to the order of Melchizedek." (Psalm 110:4)
Read the psalm straight through and one thing sets that verse apart. God speaks in verse 1 too, but there He commands: sit. In verse 4 He swears. It is the only place in the psalm where the Lord puts His own name under oath, and it's the line the writer of Hebrews cannot leave alone. Israel's kings could not touch the priesthood; that office belonged to Levi by law, and Uzziah left the temple a leper for trying. Yet here is a King promised a priesthood, from outside Levi, forever, on God's sworn word, and Hebrews spends three chapters on why that matters for how you stand with God.
The Covenant You Were Told Had Two Sides
At some point in your church life you probably heard covenant explained like this: God is faithful, and He will always keep His part, but a covenant has two parties, and you have to hold up yours. It's a fair reading on its face. Hebrews itself seems to say so.
For we have become partakers of Christ if we hold the beginning of our confidence steadfast to the end. (Hebrews 3:14)
That's the verse the two-sided reading rests on, and it deserves to be taken seriously rather than explained away. Hebrews does want its readers to hold on, and the "if" is real: holding your confidence to the end is what partaking of Christ looks like from the outside. But the letter doesn't leave "hold steadfast" hanging on your grip. When it turns to readers in danger of drifting, its remedy is not a tighter hold but a longer look at what the hope is fastened to. Three chapters later it shows you, and it starts with Abraham.
Thus God, determining to show more abundantly to the heirs of promise the immutability of His counsel, confirmed it by an oath, that by two immutable things, in which it is impossible for God to lie, we might have strong consolation. (Hebrews 6:17-18)
The writer is recalling Genesis 15 and 22, where God promised Abraham and then swore to it, and since He could swear by no one greater, He swore by Himself (Hebrews 6:13). Notice who is doing the swearing. Not the heirs. God confirms His own promise with His own oath, for people who need to know it will hold. Then the writer moves from that pattern to its fulfillment. The hope the heirs now have is an anchor of the soul, both sure and steadfast, one that enters the Presence behind the veil, where Jesus has gone ahead of us as High Priest forever according to the order of Melchizedek. Abraham's oath is the pattern. Psalm 110:4 is the oath that fulfills it, and chapter 7 picks it up from there.
Priests Without an Oath
And inasmuch as He was not made priest without an oath (for they have become priests without an oath, but He with an oath by Him who said to Him: "The LORD has sworn and will not relent, 'You are a priest forever according to the order of Melchizedek'"), by so much more Jesus has become a surety of a better covenant. (Hebrews 7:20-22)
Aaron's sons became priests by the law of Moses. The law appointed them, the law governed them, and the law replaced them when they died. God commanded that priesthood, but He did not swear to it. It could be set aside, and Hebrews says it was. Jesus became a priest on entirely different footing: an oath, spoken by God, about a priesthood that would have no successor. And the writer adds a detail that decides the order of things. The word of the oath, which came after the law, appoints the Son who has been perfected forever (Hebrews 7:28). The oath came later than Sinai, and in Hebrews' argument the later word governs: a priesthood God swore to after the law outranks the one the law had installed.
That is why the priesthood changed, and why Hebrews can say that when the priesthood changes, of necessity there is also a change of the law (Hebrews 7:12). The system that ran on Israel's obedience was administered by priests God had appointed but never sworn to. The Priest He did swear to administers a covenant of a different kind. Hebrews calls Him its surety, the one who guarantees it. And as with Abraham, God had no one greater to swear by, so whatever He swore in Psalm 110, He swore by Himself. The promise is to you. The oath was between God and God, and He will not relent.
An Anchor Holds by Where It's Fastened
Stand on a harbor wall at night and you'll see boats riding at anchor with nobody aboard. No one is gripping a rope. The vessel swings with the tide and stays where it was left, because what holds a boat is not the sailor's hands but where the anchor is set. Hebrews says your hope is fastened behind the veil, in the Presence of God, held there by a Priest whose term does not expire. The rope runs from your life into a room you can't see, and it's tied off at His end.
That doesn't make holding on meaningless. Hebrews still tells you to hold, and some days it costs something: forgiving on purpose, enduring on purpose, choosing to trust when the week argues otherwise. But you hold on from security rather than for it. Your grip was not what kept the boat in the harbor. The anchor was set by an oath, and nothing you do on deck can pull it loose, because it was sworn before you ever boarded.
The Pharisees couldn't account for a Lord that David himself bows to. Hebrews goes on to say what that Lord holds: a priesthood God swore to, and a covenant He guarantees. The psalm the New Testament reaches for more than any other is the one where God put His own name under oath about His Son, and He has not changed His mind.