Pleasant relations did not continue to subsist forever between Cyrus and Darius. A war broke out between them, in which Cyrus lost life and lands. Fearing Darius, Daniel fled to Persia. But an angel of God appeared to him with the message: "Fear not the king, not unto him will I surrender thee." Shortly afterward he received a letter from Darius reading as follows: "Come to me, Daniel! Fear naught, I shall be even kinder to thee than Cyrus was." Accordingly Daniel returned to Shushtar, and was received with great consideration by Darius.
Cyrus Among the Heavenly Host
Legends of the Jews 11:14