חֲמֵ֣שֶׁת ׀ סַרְנֵ֣י פְלִשְׁתִּ֗ים וְכָל־הַֽכְּנַעֲנִי֙ וְהַצִּ֣ידֹנִ֔י וְהַ֣חִוִּ֔י יֹשֵׁ֖ב הַ֣ר הַלְּבָנ֑וֹן מֵהַר֙ בַּ֣עַל חֶרְמ֔וֹן עַ֖ד לְב֥וֹא חֲמָֽת׃
namely, the five lords of the Philistines, and all the Canaanites, and the Zidonians, and the Hivites that dwelt in mount Lebanon, from mount Baal-hermon unto the entrance of Hamath.
Rashi on Judges
Five Pelishtite sovereignties. These were the nations whom He permited to remain as a test.
Metzudat David on Judges
FIVE: Look back on the text before this where it says "and these are the nations... five...