Once the man is captured, the path to conquering the city opens, revealing both the fulfillment of a promise and the power of divine providence. The captive reveals the city's entrance to the Israelite forces, but he does so with absolute secrecy. Rather than making a noticeable gesture, he subtly hints and points with his finger to ensure that no one else observes his actions [רש"י, רד"ק].
With the entrance exposed, the forces penetrate the city walls and strike it down with the sword [ביאור שטיינזלץ]. Remarkably, this sweeping victory is accomplished by the guards alone. This extraordinary success serves as a clear sign to them that God is present with them, actively helping a small group defeat a much larger force [מלבי"ם].
True to their word, the Israelites reward the man for his crucial assistance. While the rest of the city falls, he and his entire family are set free and spared from destruction [מצודת דוד, ביאור שטיינזלץ]. This outcome highlights the integrity of the guards, who strictly honor their agreement. Furthermore, noting the man's release serves a practical purpose in preventing geographical confusion. It makes it clear that the city of Luz conquered in this event is distinct from another city named Luz located in the land of the Hittites, which this very man goes on to build after gaining his freedom [מלבי"ם].