Titus Livius (Livy), The History of Rome, Book 26
Frank Gardner Moore, Professor Emeritus in Columbia University, Ed.

25. as Philip was wintering at Pella, the estrangement of the Aetolians¹ was reported to him. [2] accordingly, because he intended at the beginning of spring to move his army into Greece, in order that Macedonia should keep the Illyrians in her rear and the cities near them intimidated, he made a sudden incursion into the territories of Oricum and Apollonia,² and when the Apollonians came out of their city, he drove them inside their walls, causing great [p. 97]panic and alarm. [3] after ravaging the nearest parts³ of Illyricum, he changed the direction of his march with the same speed into Pelagonia. [4] then he captured a city of the Dardanians, Sintia, as likely to afford a passage for the Dardanians into Macedonia. [5] so much having been done in haste, mindful of the Aetolian war and the Roman war combined with it, he came down through Pelagonia and Lyncus⁴ and Bottiaea into Thessaly,⁵ believing that men could be aroused to join him in undertaking a war against the Aetolians, and leaving Perseus at the pass into Thessaly⁶ with four thousand armed [6??] men, to prevent the Aetolians from entering, he led his army, before he should be engaged in more important matters, into Macedonia and thence into Thrace and against the Maedi. [7] that tribe had been in the habit of making raids into Macedonia, whenever it knew that the king was engaged in a foreign war and the kingdom unprotected. [8] therefore to break its power he began at the same time to lay waste the country and to besiege the city of Iamphorynna, the capital and citadel of Maedica. [9] Scopas, on learning that the king had gone into Thrace and was there occupied with a war, armed all the young men among the Aetolians and prepared to invade Acarnania. [10] against these the Acarnanian tribe, inferior in strength, and at the same time seeing Oeniadae and Nasus lost and a war with Rome impending in addition, prepared for war out of resentment rather than calculation. [11] sending away wives and children and the older men above sixty years to the nearest part of Epirus, from fifteen years of age up to sixty [p. 99]they took an oath that they would not return except⁷ as victors; [12] should any man come out of the battle defeated, they drew up a dreadful curse upon their countrymen, a most solemn adjuration addressed to their hosts:⁸ that no one should receive that man into the city, into his house, to his table, to his hearth. [13] and at the same time they besought the Epirotes to cover under one mound all of their men who [14??] were to fall in battle, and to set up this inscription for those they had buried: “here lie the Acarnanians who, fighting for their country against the violence and injustice of the Aetolians, have met their death.” [15] having aroused their spirits by these means, they pitched camp facing the enemy at their very frontier. sending messengers to Philip to inform him how great was the danger, they compelled him to give up the war which he had on hand, after the surrender of Iamphorynna and in spite of his other successes. [16] the Aetolians' attack was delayed at first by the report of the oath of the Acarnanians, and then news of Philip's approach forced them to retire far back into the interior. [17] and Philip, although he had been making forced marches to prevent the Acarnanians from being overpowered, did not advance beyond Dium.⁹ thence, on hearing that the Aetolians had returned from Acarnania, he too returned to Pella.