Strabo Geography 9.2.11

[11] Also Mycalessus, a village, is in the Tanagraean territory. It is situated on the road that leads from Thebes to Chalcis; and in the Boeotian dialect it is called Mycalettus. And Harma is likewise in the Tanagraean territory; it is a deserted village near Mycalettus, and received its name from the chariot of Amphiaraüs, and is a different place from the Harma in Attica, which is near Phylë, a deme of Attica bordering on Tanagra. ¹ Here originated the proverb, “when the lightning flashes through Harma”; for those who are called the Pythaistae look in the general direction of Harma, in accordance with an oracle, and note any flash of lightning in that direction, and then, when they see the lightning flash, take the offering to Delphi. ² They would keep watch for three months, for three days and nights each month, from the altar of Zeus Astrapaeus; ³ this altar is within the walls ⁴ between the Pythium and the Olympium. ⁵ In regard to the Harma in Boeotia, some say that Amphiaraus fell in the battle out of his chariot ⁶ near the place where his temple now is, and that the chariot was drawn empty to the place which bears the same name; others say that the chariot of Adrastus, when he was in flight, was smashed to pieces there, but that Adrastus safely escaped on Areion. ⁷ But Philochorus ⁸ says that Adrastus was saved by the inhabitants of the village, and that on this account they obtained equal rights of citizenship from the Argives.