“To be a Cretan: People use this phrase to mean lying and cheating. And they say it developed as a proverb from Idomeneus the Cretan. For, as the story goes, when there was a disagreement developed about the greater [share] among the Greeks at troy and everyone was eager to acquire the heaped up bronze for themselves, they made Idomeneus the judge. Once he took open pledges from them that they would adhere to the judgments he would make, he put himself in from of all the rest! For this reason, it is called Kretening.”
Palaiophron did most of the work translating this and deserves the credit for the good parts. One thing to note, here Marcellus regularly speaks of τῶν ἔξωθεν which the LSJ glosses as “foreigners” (or, as my father, a Mainer, used to say “people from away”). But in ecclesiastical Greek, the phrase is equivalent to οἱ ἕξω which means “outsiders” i.e. non-Christians—in this work, the term is likely used to distinguish non-Christian sayings from the Biblical proverbs.
Marcellus, fr. 125 On Greek Proverbs
“It is not out of place, I think, to remind you at present of a few proverbs of non-Christians.
‘EITHER HE DIED OR HE TAUGHT LETTERS’ This proverb, aimed at the appearance of writing, one could take as being spoken against those who teach reading and writing, since another one among them says “You were teaching letters, I was wandering around.” Those who wrote commentaries claimed that this is not so. Rather, they say that the Sicilians—after conquering the Athenians in battle—preserved only those who supported the foundations of education and led them off as teachers for their children while slaying all of the others. A few survivors who returned, when asked by the Athenians about the men who did not fare as well, responded that it was said, ‘EITHER HE DIED OR TAUGHT LETTERS.’