Also found is '[Diomedeian] horse'.1 A proverb, [stemming] from [Diomedes [Author, Myth]] the son of Tydeus or from the Thracian [Diomedes]. The latter compelled his guests to have intercourse with his daughters and then killed them. His daughters were disgraceful (and the horses are allegories for them). Others say that Diomedes and Odysseus were returning after stealing the Palladium. Odysseus, following behind, intended to kill Diomedes; but Diomedes saw the shadow of his sword in the moonlight and, out of fear, made Odysseus lead the way, poking him in the back with his sword.2 The proverb is used to describe those who do something under compulsion. The reason for the proverb is this: because Diomedes had man-eating horses.
[Note] that3 Diomedes on his homeward journey put in to his own land, but was not welcomed. He was chased out, and he went to Calabria4 where he founded a city which he called Argyrippe; this has since changed its name to Beneventum↗.
For 'Diomedeian compulsion' see e.g. Aristophanes, Ecclesiazusae 1029; Plato, Republic 493D; Zenobius 3.8.
[By a slip, the SOL headword gives not this phrase but the opening of the gloss.]
1(This initial gloss, Adler reports, occurs in only two of the mss.) On the carnivorous horses of Diomedes [Author, Myth] -- the Thracian one about to be mentioned -- see generally OCD(4) 458, under 'Diomedes(1)'.↩