Who gave Ezra the decree to return and rebuild the temple?
Cyrus issued the decree that sent Ezra back to rebuild the temple. According to the context, Ezra went back by the decree of Cyrus to rebuild the temple that Nebuchadnezzar's forces had utterly destroyed. This return came after the Babylonian captivity.
Les explains that the return of Ezra to rebuild the temple is tied to the decree of Cyrus. This took place after the Babylonian captivity, which began when Nebuchadnezzar came in 606 B.C. and took Daniel and the Jews captive. After the seventy years of captivity, about 526 B.C., Ezra went back by Cyrus's decree to rebuild the temple that Nebuchadnezzar's forces had destroyed. Les also notes that this fits within the prophecy of 490 years from a particular time after the captivity, and that Jeremiah had prophesied the seventy-year captivity.