History of the Peloponnesian War

So by marching through the rain, and having passed the river with difficulty, they arrived too late; as some of the men had been by this time slain, and others of them were kept alive as prisoners.

When the Thebans learned what had happened, they formed a design against those of the Plataeans who were outside the city, (for there were both men and stock in the fields, inasmuch as the evil had happened unexpectedly in time of peace,) for they wished to have all they could take to exchange for their own men within, should any happen to have been taken alive. Such were their plans.

But the Plataeans, while they were still deliberating, having suspected that there would be something of this kind, and being alarmed for those outside, sent out a herald to the Thebans, saying that they had not acted justly in what had been done, by endeavouring to seize their city in time of treaty; and told them not to injure what was without; else they also would put to death the men whom they had alive in their hands; but if they withdrew again from the territory, they would give the men back to them.