Their land had been devastated by the powerful Babylon. Many of the people had been taken from their homes and transported to that foreign country. With no army, with no wealth, they did not have the power to resist.
Yet, God has not abandoned them. The powerful Persia defeats Babylon. King Cyrus, stirred by the Lord (assisted by Jeremiah), sends the exiles home, directing them to rebuild the temple. Their neighbors donated valuable items to assist in the project.