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

[526] When Eurycles had made this portentous speech, he greatly commended Antipater, as the only child that had an affection for his father, and on that account was an impediment to the other's plot against him. Hereupon the king, who had hardly repressed his anger upon the former accusations, was exasperated to an incurable degree. At which time Antipater took another occasion to send in other persons to his father to accuse his brethren, and to tell him that they had privately discoursed with Jucundus and Tyrannus, who had once been masters of the horse to the king, but for some offenses had been put out of that honorable employment. Herod was in a very great rage at these informations, and presently ordered those men to be tortured; yet did not they confess any thing of what the king had been informed; but a certain letter was produced, as written by Alexander to the governor of a castle, to desire him to receive him and Aristobulus into the castle when he had killed his father, and to give them weapons, and what other assistance he could, upon that occasion. Alexander said that this letter was a forgery of Diophantus. This Diophantus was the king's secretary, a bold man, and cunning in counterfeiting any one's hand; and after he had counterfeited a great number, he was at last put to death for it. Herod did also order the governor of the castle to be tortured, but got nothing out of him of what the accusations suggested.