M. Tullius Cicero, On his House
C. D. Yonge, Ed.

[66] And that you may be aware that that man had been an enemy not to their persons, but to their virtues, after I was driven out, and Cato despatched on his commission, he turns himself against that very man by whose advice and by whose assistance he was in the habit of saying in the assemblies that he had done and continued to do what he was then doing and everything which he had hitherto done. He thought that Cnaeus Pompeius, who he saw was in every one's opinion by far the first man in the city, would not much longer tolerate his frenzy. After he had filched out of his custody by treachery the son of a king who was our friend,—himself being an enemy and a prisoner,—and having provoked that most gallant man by this injury, he thought that he could contend with him by the aid of those troops against whom I had been willing to struggle at the risk of the destruction of all virtuous citizens, especially as at first he had the consuls to help him. But after a time Gabinius broke his agreement with him; but Piso continued faithful to him.