"'This is what Cyrus king of Persia says: "The Lord, the God of heaven, has given me all the kingdoms of the earth and he has appointed me to build a temple for him at Jerusalem in Judah. Anyone of his people among you - may his God be with him, and let him go up to Jerusalem in Judah and build the temple of the Lord, the God of Israel, the God who is in Jerusalem. And the people of any place where survivors may now be living are to provide him with silver and gold, with goods and livestock, and with freewill offerings for the temple of God in Jerusalem."'" NIV translation
During this time, King Cyrus had come to know of God through the prophet Daniel. The phrase "God of heaven" began in the book of Daniel. We see, in his proclamation, the authority that the king has to open the door for their return and the fact that he did not compel the people to go but instead gave them the opportunity. This is a picture of how Jesus opened the doors of heaven to give us the opportunity to go there to be with Him. We also see that all of God's people were required to provide the materials to build the temple. This is a picture of God's desire for all Christians to work together to bring people into His kingdom.