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

[165] While Herod had these things in his mind, there was a certain occasion afforded him: for Hyrcanus was of so mild a temper, both then and at other times, that he desired not to meddle with public affairs, nor to concern himself with innovations, but left all to fortune, and contented himself with what that afforded him: but Alexandra [his daughter] was a lover of strife, and was exceeding desirous of a change of the government, and spake to her father not to bear for ever Herod's injurious treatment of their family, but to anticipate their future hopes, as he safely might; and desired him to write about these matters to Malchus, who was then governor of Arabia, to receive them, and to secure them [from Herod], for that if they went away, and Herod's affairs proved to be as it was likely they would be, by reason of Caesar's enmity to him, they should then be the only persons that could take the government; and this, both on account of the royal family they were of, and on account of the good disposition of: the multitude to them. While she used these persuasions, Hyrcanus put off her suit; but as she showed that she was a woman, and a contentious woman too, and would not desist either night or day, but would always be speaking to him about these matters, and about Herod's treacherous designs, she at last prevailed with him to intrust Dositheus, one of his friends, with a letter, wherein his resolution was declared; and he desired the Arabian governor to send to him some horsemen, who should receive him, and conduct him to the lake Asphaltites, which is from the bounds of Jerusalem three hundred furlongs: and he did therefore trust Dositheus with this letter, because he was a careful attendant on him, and on Alexandra, and had no small occasions to bear ill-will to Herod; for he was a kinsman of one Joseph, whom he had slain, and a brother of those that were formerly slain at Tyre by Antony: yet could not these motives induce Dositheus to serve Hyrcanus in this affair; for, preferring the hopes he had from the present king to those he had from him, he gave Herod the letter. So he took his kindness in good part, and bid him besides do what he had already done, that is, go on in serving him, by rolling up the epistle and sealing it again, and delivering it to Malchus, and then to bring back his letter in answer to it; for it would be much better if he could know Malchus's intentions also. And when Dositheus was very ready to serve him in this point also, the Arabian governor returned back for answer, that he would receive Hyrcanus, and all that should come with him, and even all the Jews that were of his party; that he would, moreover, send forces sufficient to secure them in their journey; and that he should be in no want of any thing he should desire. Now as soon as Herod had received this letter, he immediately sent for Hyrcanus, and questioned him about the league he had made with Malchus; and when he denied it, he showed his letter to the Sanhedrim, and put the man to death immediately.