History of the Peloponnesian War
Thucydides
Thucydides. The history of the Peloponnesian War, Volume 1-2. Dale, Henry, translator. London: Heinemann and Henry G. Bohn, 1851-1852.
The Lacedaemonians, meanwhile, taking with them their Arcadian allies who had joined them, invaded the territory of Mantinea, and having encamped near the temple of Hercules, laid waste the land.
The Argives and their allies, on seeing them, occupied a position that was strong and difficult of access, and drew up their troops for action.
The Lacedaemonians and their allies immediately advanced against them, and proceeded to within stone's throw or arrow-shot; when one of the elders called out to Agis,
that he was purposing to cure evil with evil;meaning that his present unseasonable eagerness was intended to be a reparation of his culpable retreat from Argos.
He then, whether in consequence of this exclamation, or because he was himself suddenly struck by some resolution different from what he had before adopted, led his army back again with all speed, before the engagement had begun;