Flavius Josephus, Antiquities of the Jews
William Whiston, A.M., Ed.

[54] BUT now Artabanus, king of the Parthians perceiving that the governors of the provinces had framed a plot against him, did not think it safe for him to continue among them; but resolved to go to Izates, in hopes of finding some way for his preservation by his means, and, if possible, for his return to his own dominions. So he came to Izates, and brought a thousand of his kindred and servants with him, and met him upon the road, while he well knew Izates, but Izates did not know him. When Artabanus stood near him, and, in the first place, worshipped him, according to the custom, he then said to him, "O king! do not thou overlook me thy servant, nor do thou proudly reject the suit I make thee; for as I am reduced to a low estate, by the change of fortune, and of a king am become a private man, I stand in need of thy assistance. Have regard, therefore, unto the uncertainty of fortune, and esteem the care thou shalt take of me to he taken of thyself also; for if I be neglected, and my subjects go off unpunished, many other subjects will become the more insolent towards other kings also." And this speech Artabanus made with tears in his eyes, and with a dejected countenance. Now as soon as Izates heard Artabanus's name, and saw him stand as a supplicant before him, he leaped down from his horse immediately, and said to him, "Take courage, O king! nor be disturbed at thy present calamity, as if it were incurable; for the change of thy sad condition shall be sudden; for thou shalt find me to be more thy friend and thy assistant than thy hopes can promise thee; for I will either re-establish thee in the kingdom of Parthia, or lose my own."