1 Samuel 17:8

And he stood and cried unto the armies of Israel— Antiquity furnishes us with many examples of single combats like this proposed by Goliath. Thus Paris and Menelaus in Homer, and the Horatii and Curiatii in Livy, are said to fight at the head of the army, upon condition that the party of the vanquished should receive laws from the conqueror. And would to God that on many occasions princes would singly determine those quarrels, which, without interesting the public good, give room for such horrible effusions of innocent blood! But it does not seem very likely to have been with a view to spare human blood, that Goliath proposed this duel with such an Israelite as should be chosen. It was entirely bravado and insolence in the Philistine: who, because he was monstrous, thought himself invincible. See Buddaeus Jurisprud. Hist. Specim. sect. 21.