History of the Peloponnesian War
Thucydides
Thucydides, Vol. 1-4. Smith, Charles Foster, translator. London and Cambridge, MA: Heinemann and Harvard University Press, 1919-1923.
And when they were already drawing up for the conflict the generals of the Syracusans, seeing that their own army had become disordered and did not readily get into line, led them back to the city, all save a part of the cavalry. These remained behind and tried to prevent the Athenians from bringing stones and scattering to any great distance.
But one tribal[*](φυλή is here used for τάξις, the term being borrowed from the civil classification. Each of the ten tribes furnished a division (τάξις).) division of the Athenian hoplites, and with these all their cavalry, attacked and routed the Syracusan cavalry, killed some, and set up a trophy of the cavalry fight.
On the next day some of the Athenians proceeded to build the wall to the north of the round fort, while others brought together stones and wood and began to lay these down along the line towards the place called Trogilus, in which direction the line of circumvallation would be shortest from the Great Harbour to the outer sea.
But the Syracusans, at the suggestion of their generals, and especially of Hermocrates, were no longer inclined to risk pitched battles with their whole force against the Athenians. It seemed better to build a wall across the line where the Athenians were going to bring their wall, so that if they got ahead of them the Athenians would be blocked off, and they decided at the same time, if the Athenians should attack them while at this work, to send a part of the army against them;