The king in Psa. 45 typifies Christ as the King; the city in this psalm, and often in the Bible as a whole, signifies a kingdom. As the King, Christ needs a city in which to rule and reign. The city of God is the enlarged, strengthened, and built-up church as the ruling center for God’s reign in His kingdom. The church as the house of God (Psa. 23:6; 26:8; 27:4; 36:8; 1 Tim. 3:15) must be enlarged to become the church as the city, the kingdom, of God (Rev. 5:9-10). Eventually, in God’s economy the house of God becomes the holy city, New Jerusalem, as God’s eternal habitation and the ruling center of His eternal kingdom (Rev. 21:2-3, 22; 22:3).