Midrash su II Cronache 24:8

When the king arose from his sleep, he said to his servants, his eunuchs, who were wont to give him something to drink: Give me a little water. They brought him the golden jug, and a deadly poison || was therein. He said to them: Pour out the water before me. They said to him: O our lord, O king, this water is excellent, good, even choice. Why should we pour it out before thee? He said to them: Thus have I resolved to have it poured out before me. They poured it out before him, and he found therein the deadly poison, and he commanded that they should be hanged, as it is said, "They were both hanged on a tree" (Esth. 2:23). They were both hanged on one tree, one after the other, as it is said, "Upon a tree" (ibid.); it is not written, "Upon trees." All affairs which were enacted before the king they wrote before him, and they placed it in the king's box, and when the king wished to discover what had happened to him they read the documents, and he knew what had happened to him. So they wrote in the book the word which Mordecai had told, as it is said, "And it was written in the book of the chronicles" (ibid.).