History of the Peloponnesian War

When the news was brought to Hippias in the Cerameicus, he went at once, not to the scene of action, but to the hoplites in the procession, before they, being some distance away, had become aware of what had happened, and, disguising his looks so as to betray nothing in regard to the calamity, pointed to a certain place and ordered them to go thither without their arms.

So they withdrew, thinking that he had something to say to them; while he, ordering the mercenaries to take up the arms of the others, immediately picked out those whom he held guilty, and anyone besides who was found with a dagger; for it was customary to march in the processions armed with shield and spear only.