Xenophon Hellenica 4.7.2

[2]
  After this it seemed to the Lacedaemonians that it was not safe for them to undertake a campaign against the Athenians or against the Boeotians while leaving in their rear a hostile state bordering upon Lacedaemon and one so large as that of the Argives; they accordingly called out the ban against Argos. Now when Agesipolis learned that he was to lead the ban, and when the sacrifices which he offered at the frontier proved favourable, he went to Olympia and consulted the oracle of the god, asking whether ¹ it would be consistent with piety if he did not acknowledge the holy truce claimed by the Argives; for, he urged, it was not when the appointed time came, but when the Lacedaemonians were about to invade their territory, that they pleaded the sacred months. ² And the god signified to him that it was consistent with piety for him not to acknowledge a holy truce which was pleaded unjustly. Then Agesipolis proceeded straight from there to Delphi and asked Apollo in his turn whether he also held the same opinion as his father Zeus in regard to the truce. And Apollo answered that he did hold quite the same opinion.