And kept the feast of unleavened bread seven days with joy: for the LORD had made them joyful, and turned the heart of the king of Assyria unto them, to strengthen their hands in the work of the house of God, the God of Israel. Turned the heart of the king of Assyria - I am of Calmet's mind, that king of Assyria is here put for king of Persia. Cyrus and his successors possessed all the rights and estates of the ancient kings of Assyria, and therefore the same monarch may be styled king of Assyria as well as king of Persia.
Darius had a very high character, as a wise, just, and merciful prince. To strengthen his title to the crown, he married two of the daughters of Cyrus, and, no doubt, to show his affection to this family, he the more cheerfully confirmed the edict which Cyrus had made in favor of the Jews.
Commentary on the Bible, by Adam Clarke [1831].