Passage
And this is what you shall observe: Every male, and all women that have known men, you shall kill, but the virgins you shall save.
And this is what you shall observe: Every male, and all women that have known men, you shall kill, but the virgins you shall save.
Judges 21:9 (At that time also when they were in Silo, no one of them was found there,)
Judges 21:10 So they sent ten thousand of the most valiant men, and commanded them, saying: Go and put the inhabitants of Jabes Galaad to the sword, with their wives and their children.
Judges 21:11 And this is what you shall observe: Every male, and all women that have known men, you shall kill, but the virgins you shall save.
Judges 21:12 And there were found of Jabes Galaad four hundred virgins, that had not known the bed of a man, and they brought them to the camp in Silo, into the land of Chanaan.
Judges 21:13 And they sent messengers to the children of Benjamin, that were in the rock Remmon, and commanded them to receive them in peace.
The verse centers on "shall", "observe", "male", "women", "known", "kill", and "virgins". It is saying that the verse draws attention to "shall" and "observe", so its meaning should be read from those terms before moving to application.
The nearby context moves from verse 10's "So they sent ten thousand of the..." into verse 12's "And there were found of Jabes Galaad...", so "shall" and "observe" belong inside that flow. In Judges context, the local focus is covenant, worship, and faithfulness.
A plain takeaway is to answer the verse's own emphasis on "shall" and "observe" with trust shaped by these words, not by a vague optimism outside the passage.