Histories

When no favorable omens for battle could be won either by the Persians themselves or by the Greeks who were with them (for they too had a diviner of their own, Hippomachus of +Levkas [20.65,38.716] (island), Levkas, Ionian Islands, Greece, Europe Leucas), and the Greeks kept flocking in and their army grew, Timagenides son of Herpys, a Theban, advised Mardonius to guard the outlet of the pass over Cithaeron, telling him that the Greeks were coming in daily and that he would thereby cut off many of them.

The armies had already lain hidden opposite each other for eight days when he gave this counsel. Mardonius perceived that the advice was good, and when night had fallen, he sent his horsemen to the outlet of the pass over Cithaeron which leads towards Plataea [23.2667,38.2] (Perseus) Plataea. This pass the Boeotians call the Three Heads, and the Athenians the Oak's Heads. The horsemen who were sent out did not go in vain,