Plutarch Quaestiones Convivales 7.4.6

[6] Then I with a smile said: But, sir, that fish there, that according to the proverb is laid up, why do not we bring out into play together with Pythagoras’s choenix, which he forbids any man to sit upon, thereby teaching us that we ought to leave something of what we have before us for another time, and on the present day be mindful of the morrow? We Boeotians use to have that saying frequently in our mouths, Leave something for the Medes, ever since the Medes overran and spoiled Phocis and the marches of Boeotia; but still, and upon all occasions, we ought to have that ready, Leave something for the guests that may come. And therefore I must needs find fault with that always empty and starving table of Achilles; for, when Ajax and Ulysses came ambassadors to him, he had nothing ready, but was forced out of hand to dress a fresh supper. And when he would entertain Priam, he again bestirs himself, kills a white ewe, joints and dresses it, and in that work spent a great part of the night. But Eumaeus (a wise scholar of a wise master) had no trouble upon him when Telemachus came home, but presently desired him to sit down, and feasted him, setting before him dishes of boiled meat, But if this seems trifling, and a small matter, I am sure it is no small matter to command and restrain appetite while there are dainties before you to satisfy and please it. For those that are used to abstain from what is present are not so eager for absent things as others are.