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

[19] AFTER these promises had been given to Aretas, he made an expedition against Aristobulus with an army of fifty thousand horse and foot, and beat him in the battle. And when after that victory many went over to Hyrcanus as deserters, Aristobulus was left desolate, and fled to Jerusalem; upon which the king of Arabia took all his army, and made an assault upon the temple, and besieged Aristobulus therein, the people still supporting Hyreanus, and assisting him in the siege, while none but the priests continued with Aristobulus. So Aretas united the forces of the Arabians and of the Jews together, and pressed on the siege vigorously. As this happened at the time when the feast of unleavened bread was celebrated, which we call the passover, the principal men among the Jews left the country, and fled into Egypt. Now there was one, whose name was Onias, a righteous man be was, and beloved of God, who, in a certain drought, had prayed to God to put an end to the intense heat, and whose prayers God had heard, and had sent them rain. This man had hid himself, because he saw that this sedition would last a great while. However, they brought him to the Jewish camp, and desired, that as by his prayers he had once put an end to the drought, so he would in like manner make imprecations on Aristobulus and those of his faction. And when, upon his refusal, and the excuses that he made, he was still by the multitude compelled to speak, he stood up in the midst of them, and said, "O God, the King of the whole world! since those that stand now with me are thy people, and those that are besieged are also thy priests, I beseech thee, that thou wilt neither hearken to the prayers of those against these, nor bring to effect what these pray against those." Whereupon such wicked Jews as stood about him, as soon as he had made this prayer, stoned him to death.