Judges 21:5
“And the children of Israel said, Who is there among all the tribes of Israel that came not up with the congregation unto the Lord? For they had made a great oath concerning him that came not up to the Lord to Mizpeh, saying, He shall surely be put to death.”
And said, O Lord God of Israel, why is this come to pass in Israel, that there should be to day one tribe lacking in Israel?
And it came to pass on the morrow, that the people rose early, and built there an altar, and offered burnt offerings and peace offerings.
And the children of Israel said, Who is there among all the tribes of Israel that came not up with the congregation unto the Lord? For they had made a great oath concerning him that came not up to the Lord to Mizpeh, saying, He shall surely be put to death.
And the children of Israel repented them for Benjamin their brother, and said, There is one tribe cut off from Israel this day.
How shall we do for wives for them that remain, seeing we have sworn by the Lord that we will not give them of our daughters to wives?
Counter-Arguments
The strongest case that this verse does not belong in this theme.

Cross-References
“And that whosoever would not come within three days, according to the counsel of the princes and the elders, all his substance should be forfeited, and himself separated from the congregation of those that had been carried away.”
“And to the Canaanite on the east and on the west, and to the Amorite, and the Hittite, and the Perizzite, and the Jebusite in the mountains, and to the Hivite under Hermon in the land of Mizpeh.”
“And Dilean, and Mizpeh, and Joktheel,”
“Then all the children of Israel went out, and the congregation was gathered together as one man, from Dan even to Beer–sheba, with the land of Gilead, unto the Lord in Mizpeh.”
“And all the people arose as one man, saying, We will not any of us go to his tent, neither will we any of us turn into his house.”