History of the Peloponnesian War
Thucydides
Thucydides. The history of the Peloponnesian War, Volume 1-2. Dale, Henry, translator. London: Heinemann and Henry G. Bohn, 1851-1852.
When he could not convince either the generals or the soldiers, having subsequently communicated his views to the subordinate officers also, he remained quiet from stress of weather; till the soldiers themselves, in their want of occupation, were seized with a desire to set to and fortify the post.
Accordingly they took the work in land, and proceeded with it, though they had no iron tools, but carried stones just as they picked them up, and put them together, as they severally might happen to fit; while the mortar, wherever it was necessary to use any, for want of hods they carried on their back, stooping down in such a way that it might best he on, and clasping their hands behind them, to prevent its falling off.
Indeed in every way they made haste to anticipate the Lacedaemonians, by completing the most assailable points of tie work before they came to the rescue; for the greater part of the position was strong by nature, and had no need of fortifications.
Now the Lacedaemonians happened to be celebrating a festival; and, moreover, when they heard it, they made light of it, thinking that when they took the field, either the enemy would not wait their attack, or they should easily take the place by storm. To a certain extent also the fact of their army being still before Athens delayed them.