Ezra 5:13

But in the first year of Cyrus the king of Babylon the same king Cyrus made a decree to build this house of God.

In his first year as king of Babylon, Cyrus issued a decree that the house of God at Jerusalem should be rebuilt. That decree also provided that the expense of the rebuilding should be paid out of the king's treasury.

The decree was afterward found and confirmed by Darius, so that the returned exiles were allowed to continue building and provision was made for the work. Thus the verse identifies Cyrus's decree as the basis on which the temple was rebuilt, and shows the Lord's providence enabling the work to go forward despite opposition.