they were deported about 70 years before.
538 BC the army of Cyrus entered the country from the north. In June the Babylonian army was completely defeated
Cyrus now assumed the title of "king of Babylon," claimed to be the descendant of the ancient kings, and made rich offerings to the temples. At the same time he allowed the foreign populations who had been deported to Babylonia to return to their old homes, carrying with them the images of their gods. Among these populations were the Jews, who, as they had no images, took with them the sacred vessels of the temple.
EZRA 1:1-4
1 In the first year of Cyrus king of Persia, in order to fulfill the word of the Lord spoken by Jeremiah, the Lord moved the heart of Cyrus king of Persia to make a proclamation throughout his realm and also to put it in writing:
2 “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. 3 Any of his people among you may go up to Jerusalem in Judah and build the temple of the Lord, the God of Israel, the God who is in Jerusalem, and may their God be with them. 4 And in any locality where survivors may now be living, the people are to provide them with silver and gold, with goods and livestock, and with freewill offerings for the temple of God in Jerusalem.’”
The Cyrus Cylinder, an ancient clay cylinder inscribed with a declaration in the name of Cyrus referring to restoration of temples and repatriation of exiled peoples,