Ezra 7:10

To teach in Israel] Ezra, though like Zerubbabel he led a body of settlers to Jerusalem, is never styled 'Tirshatha' (as Zerubbabel is in Ezra 2:63), and his mission appears to have had purely religious ends in view. The Jews who remained in Babylon, and who were surrounded by a population wholly heathen, were marked off from their neighbours by a much deeper line of cleavage than were the Jews of Palestine, and a higher standard of religious devotion prevailed amongst them: consequently when the religious laxity of the people of Jerusalem became known at Babylon, Ezra was sent to enquire into it (Ezra 7:14), to introduce reforms, and, by authority of the Persian king, to enforce the observance of the Law by means of penalties (Ezra 7:26).