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

[534] MOREOVER, Salome exasperated Herod's cruelty against his sons; for Aristobulus was desirous to bring her, who was his mother-in-law and his aunt, into the like dangers with themselves; so he sent to her to take care of her own safety, and told her that the king was preparing to put her to death, on account of the accusation that was laid against her, as if when she formerly endeavored to marry herself to Sylleus the Arabian, she had discovered the king's grand secrets to him, who was the king's enemy; and this it was that came as the last storm, and entirely sunk the young men when they were in great danger before. For Salome came running to the king, and informed him of what admonition had been given her; whereupon he could bear no longer, but commanded both the young men to be bound, and kept the one asunder from the other. He also sent Volumnius, the general of his army, to Caesar immediately, as also his friend Olympus with him, who carried the informations in writing along with them. Now as soon as they had sailed to Rome, and delivered the king's letters to Caesar, Caesar was mightily troubled at the case of the young men; yet did not he think he ought to take the power from the father of condemning his sons; so he wrote back to him, and appointed him to have the power over his sons; but said withal, that he would do well to make an examination into this matter of the plot against him in a public court, and to take for his assessors his own kindred, and the governors of the province. And if those sons be found guilty, to put them to death; but if they appear to have thought of no more than flying away from him, that he should moderate their punishment.