What does Judges 20:2 mean?

Israel's response to the gruesome packages sent by the Levite (Judges 19:29–30) must have been greater than he imagined. The Levite cut the body of his murdered concubine into twelve pieces, sending them throughout Israel. This was almost certainly accompanied by an account of her rape and murder at the hands of the men of Gibeah (Judges 19:22–28).

Leaders of the other eleven tribes of Israel are shocked and outraged at the evil perpetrated by these men of the tribe of Benjamin (Judges 19:14). Clearly, events had been discussed enough that Israel's response was already decided. What's described here is not merely a meeting, it is a mustering of troops in massive numbers.

The total number of troops is subject to debate among scholars. The Hebrew term 'eleph can mean "thousands," but it is also used for "clans" and "divisions" (Judges 6:15). For context, a force of 400,000 would have exceeded the size of the greatest armies of ancient history. This figure does not include the 26 'eleph which Benjamin will rally as an opposing force. Scripture notes explicitly that Israel was never expected to take Canaan through overwhelming numbers (Deuteronomy 7:1). All the same, the exact number is not especially important to the story. What's clear is that every tribe—other than Benjamin (Judges 20:3)—is prepared for a fight.

The encouraging aspect of this passage is the rare moment of unity. At least for now, Israel sees themselves as a single nation belonging to the Lord and are willing to follow His direction.