Where Do You Buy That Incense?

Diodorus of Sinope, The Heiress, quoted by Athenaeus 6.239 e-f (translated by C.B. Gulick):

And so, in later times, certain rich men, imitating the example of Heracles, picked out parasites to support, and invited them in, selecting not the finest men, but those best able to play the flatterer and praise them in everything. Why! When a patron, after eating radishes or a stale sheat-fish, belches in their faces, the flatterers say that he must have lunched on violets and roses. And when the patron breaks wind as he lies next to one of these fellows, the latter applies his nose and begs him to tell him, "Where do you buy that incense?"