Isaiah 40 (today's reading is Isaiah 40:21-31) marks a shift in the tone for the entire book. The Babylon invasion, the destruction of the Temple, and the exile, when Israelites were sent to live, labour, and be confined in the heart of the enemy empire, is coming to an end. It's possible that Isaiah 40 is a conversation directed towards those members of the community who lived their lives away from home. Several generations had grown up in Babylon and would only know Jerusalem through the tales their parents and grandparents told. But Babylon has now been defeated by the Persians. The Persian Emperor, Cyrus, has decided to send the Jewish people back to Jerusalem. But Jerusalem had not been rebuilt. The temple no longer existed. Even the walls surrounding the city were broken. Living in Babylon was hard but the people at least knew what to expect there. Jerusalem, the city of God, was desolate. The people had no idea what they would find, or how they would survive, once they got there. 

This passage serves as a hopeful reminder to the people of Israel that God is with them. God understands that the future looks uncertain. God understands that the people of Israel had seen their nation destroyed and the empire that destroyed them defeated by another empire. The people felt small but God promises them that the presence of God is with them. Empires will come and go but God's love for God's people will not be undone. 

It is possible that some elderly members of the community would have been around to see the Temple restored after the return to exile. And those last few verses might point to their faithfulness. Even in the face of defeat and struggle, they were faithful in telling the story of God to their children and their children's-children. They believed that God stood with them even though God's Temple was gone. That's how they served God. And they were able to maintain the faith because God was with them. God's steadfast love does not depend on armies, empires, or power. God's loves people because that's just what God does.