Background
A psalm performed by sons of Korah. Jerusalem and Babylon were mentioned, thus this Psalm was probably written after the fall of Assyrian, and before the exile of Judah by Babylon. The theme is about the citizens of Zion.
Division
v1-3: City of God
v4-6: Citizens of God’s city
v7: Citizens rejoice in the God
Exposition
v1: [His foundation] means God founded the city of Zion among holy mountains.
v2:Gates of Zion. Gates are where worshipers enter into Jerusalem to worship God. God desires people to come into His chosen city to worship Him. Zion is the other name for Jerusalem. It is mainly used by psalmists, it means Jerusalem is not just a city, it is the God chosen holy city. God loves Zion more than all the other places in Israel. This shows that God is the sovereign God, He choose His city, His people, and His church based on His good pleasure and His good will.
v3: I believe Zion is an image of God’s church. In OT, God’s present was in Zion. In NT, God’s present is in His church. Zion is a glorious city. God’s church is a glorious organism, it is the living body of Christ.
v4-5: Rahab was a monster of ancient pagan mythology, it means arrogant. It is also used to symbolize Egypt, enemy of Israel in the south. Babylon was the enemy from the North. Philistia and Tyre were the enemies from the west. Ethiopia was Cush in Africa. All these pagans country would have people who were born in Zion and became its citizen. Salvation came from the Jew (John 4:22), but praise God it is for all the nations in the world. When we believed in Jesus as our Savior, we immediately were born into the Kingdom of God, the city of Zion, the church of Christ (John 3:5-6).
v6: God cares about every single citizen of Zion, He counted every single one who was born into Zion.
v7: Springs is a metaphor for the source of joy. Zion was not built near a great river. So it was always a problem to supply enough water. Jesus is our spring of joy. In Him we find the spring of living water (John 4:10-14).