What does Judges 7:24 mean?
The survivors of the Midianite horde (Judges 7:19–23) are fleeing east from Gideon's army. That force started the nighttime attack with only 300 men but is quickly growing to much larger size. The call has gone out to several local tribes, telling them to join the attack on Israel's oppressors (Judges 6:1–5). Those sent away just before from the initial "attack" on the Midianites (Judges 7:2–9) were probably the first assigned to chase down the fleeing enemy and destroy them before they can escape across the Jordan.The problem, for now, is that Gideon's men are chasing the enemy, and need to stop them from reaching a particular objective. Israel needs someone to secure river crossings at the Jordan, where the Midianites and their allies will attempt to cross back over into their own countries. Gideon's forces won't be able to outrun their enemy in time to stop them from getting away.
So, Gideon sends messengers—in this context, meaning individual runners or riders, who can move much faster than a large group—to call the men of Ephraim into the battle. He specifically commands they race to the Jordan River and cut off all the crossing points the Midianites might use to escape. This will trap the Midianites between the men of Ephraim at the Jordan and Gideon's pursuing forces. The specific location of Beth-barah is unknown to modern scholars.