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

[229] BUT still the affairs of Herod's family were no better, but perpetually more troublesome. Now this accident happened, which arose from no decent occasion, but proceeded so far as to bring great difficulties upon him. There were certain eunuchs which the king had, and on account of their beauty was very fond of them; and the care of bringing him drink was intrusted to one of them; of bringing him his supper, to another; and of putting him to bed, to the third, who also managed the principal affairs of the government; and there was one told the king that these eunuchs were corrupted by Alexander the king's son with great sums of money. And when they were asked whether Alexander had had criminal conversation with them, they confessed it, but said they knew of no further mischief of his against his father; but when they were more severely tortured, and were in the utmost extremity, and the tormentors, out of compliance with Antipater, stretched the rack to the very utmost, they said that Alexander bare great ill-will and innate hatred to his father; and that he told them that Herod despaired to live much longer; and that, in order to cover his great age, he colored his hair black, and endeavored to conceal what would discover how old he was; but that if he would apply himself to him, when he should attain the kingdom, which, in spite of his father, could come to no one else, he should quickly have the first place in that kingdom under him, for that he was now ready to take the kingdom, not only as his birth-right, but by the preparations he had made for obtaining it, because a great many of the rulers, and a great many of his friends, were of his side, and those no ill men neither, ready both to do and to suffer whatsoever should come on that account.