[Meaning] the slaves in Thessaly,[1] but not born as such. When the Boiotians had been defeated by Haimon at Arne they did not flee from enslavement to their conquerors but remained until the third generation, taking delight in their land. They surrendered themselves on the basis of an oath that they would suffer nothing as they worked and would not be expelled from their land. And being called Menestai, from remaining, their name later became Penestai, by the corruption of the [initial] letter.[2]
Those whom in Sparta they call Helots, these [the] Thessalians call Penestai. Thessalians and Spartans alike use the word of those who have been conquered in war and are the slaves of their conquerors.[3]
Demosthenes in the [speech] Against Aristokrates [mentions them].[4] Amongst Thessalians "penestai" is the name for what the Spartans call Helots. He[5] says that they are called not only penestai but also Thessalics.
Aristophanes [writes]: "associating with the penestai".[6]