Judges 21:3

And said, O Lord God of Israel
Jehovah, the only living and true God, the Being of beings, eternal, immutable, omnipotent and omnipresent, the God of all Israel, of the twelve tribes of Israel, their covenant God and Father; who had shown favour to them in such a peculiar and gracious manner, as he had not to other nations, and therefore hoped he would still have a kind regard unto them, and suffer them to expostulate with him in the following manner:

why is this come to pass in Israel;
expressing, as Abarbinel thinks, a concern for the 40,000 men of Israel which fell in the two first battles; but it manifestly refers to the case in the next words:

that there should be today one tribe lacking in Israel;
meaning the tribe of Benjamin, which was all destroyed, excepting six hundred men, and these had no wives to propagate the tribe; and therefore, unless some provision could be made for that, it must in a short time be totally extinct; for which they express great concern, it not being their intention when they made the above oath to extirpate them; but such were now the circumstances of things in Providence, that it must perish unless some way could be found to relieve it, and which their oath seemed to preclude; and this threw them into great perplexity.