דברים, פרק ז׳, פסוק כ׳

As the Israelites prepared to enter their new land, God promised them more than just assistance in direct, frontline battles. He assured them of a special divine intervention designed to track down and eliminate the last remaining enemies hiding in secret locations. This guarantee completed their victory by neutralizing the threat of sudden ambush from survivors emerging from mountain caves and hidden refuges.

The exact nature of this divine weapon is the subject of different interpretations. The primary approach among commentators is that God sent a swarm of venomous flying insects to attack the enemy [רש״י, מזרחי, רבנו בחיי, ביאור שטיינזלץ]. Others, however, suggest it was not an insect at all. Some view it as a severe physical illness similar to leprosy [אבן עזרא, חזקוני], while others understand it more broadly as a deep sorrow, trouble, or plague that gradually weakened the opposing forces [בכור שור, שפתי כהן].

Following the perspective that this was a flying insect, the plague is understood as a hidden miracle. Unlike the grand, open wonders performed previously, this intervention operated quietly through the forces of nature [רבנו בחיי]. The insects served a dual purpose: they traveled ahead of the Israelites to strike the enemy before the battle even began, and they remained afterward to hunt down fleeing survivors in rugged areas where the Israelites could not reach them [ביאור יש״ר, מלבי״ם]. While the primary account of the land's conquest does not detail these specific events, later historical records in the Book of Joshua confirm that this insect invasion did indeed take place [שד״ל].

Tradition describes the attack of these insects as remarkably severe. They would inject venom into the hiding enemies, blinding them from above and castrating them from below [רש״י, מזרחי, רבנו בחיי]. This specific punishment conceptually mirrors the fate of the survivors. By losing their sight, the enemies were effectively cut off from seeing the world, and by losing their reproductive abilities, they were prevented from leaving any future descendants behind [משכיל לדוד].

There is also a tradition that these insects arrived in two distinct waves, one during the leadership of Moses and another under Joshua. These two swarms corresponded to the two types of enemies they faced: the first wave targeted those who had survived the initial battles but remained out in the open, while the second wave penetrated deep into concealed spaces to root out those in hiding [אדרת אליהו]. Ultimately, whether the divine instrument was a swarm of insects, a debilitating disease, or another natural disaster such as stones falling from the sky [רלב״ג], the result was absolute. God's providence ensured the complete and final eradication of the threat facing the Israelites.