Plutarch, The Life of Cato the Younger 13

In Syria, too, as we are told, he had a laughable experience. As he was walking into Antioch, he saw at the gates outside a multitude of people drawn up on either side of the road, among whom stood, in one group, young men with military cloaks, and in another, boys with gala robes, while some had white raiment and crowns, being priests or magistrates. 

Cato, accordingly, thinking that this could only be some honorable reception which the city was preparing for him, was angry with his servants who had been sent on in advance, because they had not prevented it; but he ordered his friends to dismount, and went forward on foot with them. 

When, however, they were near the gate, he who was arranging all these ceremonies and marshaling the crowd, a man now well on in years, holding a wand and a crown in his hand, advanced to meet Cato, and without even greeting him asked where they had left Demetrius and when he would be there. 

Now, Demetrius had once been  a slave of Pompey, but at this time, when all mankind, so to speak, had their eyes fixed upon Pompey, he was courted beyond his deserts, since he had great influence with Pompey. 

Cato's friends accordingly, were seized with such a fit of laughter that they could not recover themselves even when they were walking through the crowd; but Cato was greatly disturbed at the time, and said: "O the unhappy city!" and not a word besides. 

In after times, however, he was wont to laugh at the incident himself also, both when he told it and when he called it to mind.