An approaching day of disaster stands as an unprecedented historical event, blanketing the land in absolute darkness and bringing a destructive force without equal. The primary approach among commentators is that this event is a severe locust plague. The swarming insects are metaphorically described as a nation because they join together and move with the precision of an organized military [אבן עזרא, מצודת דוד]. As this massive swarm fills the sky, it completely blocks out the sun, plunging the land into deep shadows [רד״ק, אבן עזרא]. The severity of the situation escalates as the gloom deepens into a tangible, heavy darkness, and ordinary clouds thicken into an impenetrable fog [מלבי״ם, מצודת ציון]. Beyond the physical shadow cast by the insects, this darkness also serves as a powerful metaphor for trouble and sadness, standing in sharp contrast to the light of joy [רד״ק].
The sudden arrival of this disaster is compared to the morning light spreading over mountain peaks. Just as dawn touches the highest elevations and sweeps across the world in an instant, the locust swarm will cover the land with shocking speed [רד״ק, אבן עזרא, רש״י, מצודת דוד]. Adding to this visual, the wings of the locusts will catch the light, appearing from a distance as a bright, shining wave cutting through the gloom [מלבי״ם]. This catastrophic event is marked as completely unique in history. Because a similar promise of unprecedented severity was made regarding the locust plague in Egypt, a distinction is drawn between the two. While Egypt suffered from a far greater quantity of a single locust species, the current disaster is unparalleled because it involves four entirely different species of pests attacking together or in rapid succession [רש״י, רד״ק, אבן עזרא, מלבי״ם]. Following this devastation, a promise is given that a plague of this specific nature will never strike the world again [מצודת דוד, רד״ק].
In contrast to the physical plague, another perspective views the approaching doom as a historical prophecy foretelling the destruction of the First Temple. In this context, the vast, organized force is not a swarm of insects, but the mighty foreign army of Nebuchadnezzar. The heavy clouds and deep darkness represent the profound suffering of the destruction, perhaps even pointing to the tragic day of the Ninth of Av [אברבנאל]. Through this historical lens, the image of dawn spreading over the mountains takes on a darker meaning. Rather than morning light, the concept is rooted in a word for blackness, indicating that absolute gloom will drape the landscape [אברבנאל]. Furthermore, the promise that such a massive force will not return for generations simply means that an army of this magnitude will not be seen again until centuries later, when Titus arrives to destroy the Second Temple [אברבנאל].