History of the Peloponnesian War

Immediately on their arrival, the Syracusans prepared to attack the Athenians again on both sides, by sea and by land. When the Athenian generals, on the other hand, saw that a fresh force had joined them, and that their own circumstances at the same time were not improving, but were daily becoming worse, and most especially were depressed through the sickness of the men, they repented of not having removed before. And as even Nicias did not now oppose them in the same degree, except by begging them not openly to vote on the question, they gave orders, as secretly as they could, for all to sail out of their station, and to be ready when the signal should be given.

And when, after all was in readiness, they were on the point of sailing away, the moon was eclipsed; for it happened to be at the full. The greater part therefore of the Athenians urged the generals to stop, regarding the matter with religious scruple; and Nicias (for he was somewhat over addicted to superstition, and such feelings,) declared that he would not now so much as consider the matter, with a view to moving, until, as the soothsayers directed, he had waited thrice nine days. And so the Athenians, having been stopped on this account, remained in the country.