Plutarch, Aussprüche von Spartanern ((Moralia 209 A-B):

Tissaphernes (1), at the outset, in fear of Agesilaus, made a treaty, agreeing that the king should leave him the Greek cities (2) free and independent, but, after sending for a great army from the king, he declared war on Agesilaus unless he should depart from Asia. Agesilaus gladly welcomed the transgression, and set forth as if he were intending to advance into Caria; and when Tissaphernes had concentrated his forces there, Agesilaus, by a rapid movement thence, invaded Phrygia; and having taken many cities and a wealth of spoil, he said to his friends, “To do wrong after making a treaty is impious, but to outwit the enemy is not only right and reputable, but also pleasant and profitable. [ἐπισπεισάμενον μὲν ἀδικεῖν ἀσεβές, τοὺς δὲ πολεμίους παραλογίζεσθαι οὐ μόνον δίκαιον καὶ ἐπίδοξον, ἀλλὰ καὶ ἡδὺ καὶ κερδαλέον.]”

[Plutarch, Moralia III. Ed. by Frank Cole Babbitt. Cambridge (Mass.)/London ⁷2004, pp. 246-249]

(1) Satrap von Karien
(2) in Ionien, an der kleinasiatischen Küste

Vgl. Plutarch, Leben des Agesilaos 9 (600C) sowie bei Xenophon, Diodoros Siculus, Polyainos, Cornelius Nepos und Frontinus.