Wisdom from the Early Cynics, Diogenes 6

Observing Plato one day at a costly banquet taking olives, "How is it," he said, "that you the philosopher who sailed to Sicily for the sake of these dishes, now when they are before you do not enjoy them?" 

"No, by the gods, Diogenes," replied Plato, "there also for the most part I lived upon olives and such like." 

"Why then," said Diogenes, "did you need to go to Syracuse? Was it that Attica at that time did not grow olives?" 

But Favorinus in his Miscellaneous History attributes this to Aristippus. 

Again, another time he was eating dried figs when he encountered Plato and offered him a share of them. 

When Plato took them and ate them, he said, "I said you might share them, not that you might eat them all up." 

—Diogenes Laërtius, 6.25