History of the Peloponnesian War

And therefore, they said, they did not break the oath of their league by rejecting the peace with Athens. For having sworn unto them by the gods, they should in betraying them offend the gods. And whereas it is said unless some god or hero hinder it, this appeareth to be a divine hindrance.

Thus they answered for their old oath. Then, for their league with the Argives, they gave this answer:

that when they had advised with their friends, they would do afterwards what should be just. And so the ambassadors of Lacedaemon went home. At the same time were present also in Corinth the ambassadors of Argos to invite the Corinthians to their league, and that without delay. But the Corinthians appointed them to come again at their next sitting.