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

[58] At this time Herod commanded Pheroras, that since he was so obstinate in his affection for his wife, he should retire into his own tetrarchy; which he did very willingly, and sware many oaths that he would not come again till he heard that Herod was dead. And indeed when, upon a sickness of the king, he was desired to come to him before he died, that he might intrust him with some of his injunctions, he had such a regard to his oath, that he would not come to him; yet did not Herod so retain his hatred to Pheroras, but remitted of his purpose [not to see him], which he before had, and that for such great causes as have been already mentioned: but as soon as he began to be ill, he came to him, and this without being sent for; and when he was dead, he took care of his funeral, and had his body brought to Jerusalem, and buried there, and appointed a solemn mourning for him. This [death of Pheroras] became the origin of Antipater's misfortunes, although he were already sailed for Rome, God now being about to punish him for the murder of his brethren, I will explain the history of this matter very distinctly, that it may be for a warning to mankind, that they take care of conducting their whole lives by the rules of virtue.