History of the Peloponnesian War

So that what by the foulness of the way and what by the difficulty of passing the river, they arrived not till their men were already some slain and some taken prisoners.

When the Thebans understood how things had gone, they lay in wait for such of the Plataeans as were without (for there were abroad in the villages both men and household stuff, as was not unlikely, the evil happening unexpectedly and in time of peace), desiring, if they could take any prisoners, to keep them for exchange for those of theirs within, which (if any were so) were saved alive.

This was the Thebans' purpose. But the Plataeans, whilst they were yet in council, suspecting that some such thing would be done and fearing their case without, sent a herald unto the Thebans whom they commanded to say that what they had already done, attempting to surprise their city in time of peace, was done wickedly, and to forbid them to do any injury to those without, and that otherwise they would kill all those men of theirs that they had alive, which, if they would withdraw their forces out of their territory, they would again restore unto them.