Ezra 6:21-22

21The Passover was eaten by the sons (descendants) of Israel (Jacob) who returned from exile and by all those who had separated themselves from the [ceremonial] uncleanness of the nations of the land to join them, in order to seek the Lord God of Israel.

22They observed the Feast of Unleavened Bread for seven days with joy, for the Lord had caused them to rejoice and had turned the heart of the king of Assyria toward them, so that he encouraged them and strengthened their hands in the work of the house of God, the God of Israel.