יואל, פרק ב׳, פסוק ד׳

The threatening advance of a locust swarm moves with the intensity of a charging cavalry. The primary approach among commentators is that equating these insects to horses does not refer to their physical appearance, but rather to their rapid speed. However, another perspective suggests that beyond their swift movement, the actual shape of a locust's head and back visually resembles a horse [ביאור שטיינזלץ].

As they sweep across the land, the locusts advance in a highly organized formation, much like skilled riders in a military unit [ביאור שטיינזלץ]. Their movement is a swift, relentless pursuit [מצודת ציון]. There is a profound distinction between the running of wild horses and the charge of a directed cavalry. While a horse possesses a natural strength to run with thunderous noise, it moves even faster and with greater purpose when guided by a human rider. In the same way, the locust swarm does not advance merely on its own natural instincts. Instead, it is driven by a higher power forcing it forward. It is the direct command and decree of God that "rides" upon the swarm, guiding and directing its relentless path [מלבי״ם].