Facing a massive enemy army equipped with advanced weaponry naturally triggers deep anxiety. When confronted with an overwhelming force, human nature instinctively yields to fear, often accompanied by the worry that personal sins might prevent the miracles needed for survival. To counter this, God steps in to calm Joshua, assuring him not to be afraid [חומת אנך]. This reassurance directly applies an earlier Biblical promise regarding warfare, which guarantees that fighters should not be intimidated even when facing formidable horses and chariots [מלבי״ם].
Alongside the promise of victory, God issues a specific instruction to completely destroy the enemy's military equipment. The horses are to be crippled and the chariots burned. Crippling the horses involves damaging or removing their hooves so they can no longer run [ביאור שטיינזלץ]. This action is compared to uprooting a plant, as the legs serve as the very foundation of the animal [מצודת ציון].
The commentators offer two complementary reasons why the Israelites are told to destroy these valuable spoils of war rather than use them. From a practical standpoint, the Israelites simply lack the training to fight with horses and chariots. Therefore, destroying the equipment ensures the enemy cannot recover and reuse it against them [ביאור שטיינזלץ]. However, the primary approach among commentators emphasizes a deeper spiritual motive. The destruction prevents the Israelites from claiming these advanced weapons and relying on them in future conflicts. If they were to adopt this technology, they might begin to attribute their success to their own military might. By eliminating the horses and chariots, God ensures that the Israelites place their trust entirely in Him, recognizing clearly that He is the one who secures their victories, not their physical power [רלב״ג]. This concept perfectly aligns with the Biblical law that strictly limits a king of Israel from acquiring too many horses [מלבי״ם].