David builds this short psalm in three movements, and kingship runs through all of them: God's rule established in creation, the conditions for approaching that King, and the King welcomed home in procession.
1"The earth is the LORD's and the fullness thereof." He has founded it on the seas and established it on the rivers, and nothing is left over. Nothing in the world belongs to a rival, and no chaos has to be defeated before the earth can stand. He founds it, and it stands, and everyone in it belongs to him.
Then the tone turns personal. 3"Who shall ascend the hill of the LORD? And who shall stand in his holy place?" It sounds like an entrance liturgy, the question a worshiper would face at the temple gate. The answer: 4"clean hands and a pure heart," and a refusal to lie or swear falsely. The requirement runs two directions at once, hands toward other people and heart toward God, honest in both. No honest reader can claim it. The psalm already knows that. 5"He will receive blessing from the LORD and righteousness from the God of his salvation." The verb is receive. The righteousness the psalm demands for entry is the thing verse 5 says is given, a gift handed to the worshiper.
The third movement is the most vivid, and many readers connect it with the ark's arrival in Jerusalem (2 Samuel 6), God's throne carried through the city gates. The command is addressed to the gates as though they were alive: lift up your heads, O gates, and be lifted up, O ancient doors. The gates are told to make room for a King whose only sign in the procession was a box with no image in it.
Then comes the question, asked twice and answered twice. 8"Who is this King of glory?" The first answer: the LORD, 8"strong and mighty." The second is fuller: 10"The LORD of hosts, he is the King of glory!" The repetition is delay on purpose, letting anticipation build until the full answer lands: the commander of every army in heaven and earth, entering gates that were never strong enough to keep him out.
The New Testament follows him through gates no earthly hand built. He "sat down at the right hand of the Majesty on high" (Hebrews 1:3). The hill of the LORD, once a single mount in Jerusalem, is now for his people "to Mount Zion and to the city of the living God" (Hebrews 12:22). And the psalm's question, who may ascend there, has the same answer it always had: those who receive, as a gift, the righteousness that only this King possessed on his own.
Ask what gate in your own life has stayed shut against him, a habit of mind, an old grievance, a room you keep locked. The psalm addresses the doors directly. Lift them, and let the King in.
Prayer
Father, the earth and everything in it has always been yours, and we have lived as though we belonged to ourselves. We have no clean hands or pure heart of our own, so we ask for the blessing and righteousness you give to those who seek your face. Lift up whatever gates in us have stayed shut against you, and let the King of glory come in, the LORD of hosts, strong and mighty. In Jesus' name, amen.