History of the Peloponnesian War

But when they were urgent for setting sail, the Corinthians were not disposed to accompany them before they had kept the Isthmian festival, for which that was the time. Agis expressed to them his willingness that they (according to what they urged) should not break the Isthmian truce, but that he should make the expedition on his own responsibility.

When, however, the Corinthians did not agree to this, but a delay was caused in the matter, the Athenians the more easily gained intelligence of the designs of the Chians; and sending Aristocrates, one of their generals, charged them with the fact, and on their denying it, commanded them to send with them some ships, as a pledge of good faith in their alliance.

Accordingly they sent seven. The reason of the ships being sent was, that the majority of the Chians were ignorant of the negotiations; while the few who were privy to them were both unwilling at present to incur the hostility of their commons, before they had gained some strength, and no longer expected the Peloponnesians to come, since they had so long delayed.