Albert Barnes Commentary Judges 21:3

"And they said, O Jehovah, the God of Israel, why is this come to pass in Israel, that there should be to-day one tribe lacking in Israel?" — Judges 21:3 (ASV)

The repetition of the name of Israel is very striking in connection with the title of Yahweh as “God of Israel.” It contains a very forcible pleading of the covenant, and memorial of the promises. The very name “Israel” comprehended all the twelve tribes; with one of them blotted out, the remnant would not be Israel.