דברי הימים ב, פרק י״א, פסוק י״ב

A secure kingdom requires both physical defenses and the unwavering loyalty of its people. The establishment of the southern kingdom involved a massive, two-pronged approach focused on military readiness and national unity. Weapons were distributed across the entire region, ensuring that even ordinary towns, not just the officially fortified cities, were fully equipped for battle [מלבי״ם]. The arsenals were stocked with heavy military gear, specifically large protective shields and spears [מצודת ציון, ביאור שטיינזלץ]. This widespread strengthening effort focused heavily on securing the national borders [ביאור שטיינזלץ] and outfitting the cities with a wide variety of defensive measures to withstand any threat [מצודת דוד].

Beyond physical weapons, the kingdom's true power came from its demographic and political stability. The tribes of Judah and Benjamin were completely loyal to the crown. This absolute internal cohesion stood in sharp contrast to the rival northern kingdom led by Jeroboam, which was actively losing citizens who chose to defect and support the southern kingdom [מלבי״ם]. Ultimately, this combination of intense military fortification and deep national unity created a powerful deterrent. Seeing this overwhelming strength, the king of Israel backed down, realizing that launching an attack to conquer these territories would be impossible [מצודת דוד].