שמות, פרק י׳, פסוק י״ט

The sudden end of the locust invasion unfolds through the exact same natural forces that initiated it, yet driven by an opposing and overwhelming power. God summoned an exceptionally fierce western wind blowing from the Mediterranean to counter the eastern wind that had originally brought the swarm [אבן עזרא, קאסוטו, רשב״ם, בכור שור, חזקוני]. Rather than merely altering the existing breeze, God forged an entirely new wind of immense strength to overpower the remnants of the previous weather system and carry the insects far away [רש״ר הירש, קאסוטו, מלבי״ם].

This powerful gust forcefully hurled and drowned the locusts in the Red Sea, located to the east of Egypt [אבן עזרא הקצר, קאסוטו, חזקוני]. One might wonder why God did not simply use the original eastern wind to blow the locusts back toward the west. This reflects a spiritual principle that an agent of destruction cannot serve as an agent of salvation; the wind that delivered the disaster could not be the one to remove it [משכיל לדוד]. Furthermore, casting them into the Red Sea prevented the swarm from devastating other lands [קונטרס חיבה יתירה]. It also served as a dark, symbolic foreshadowing for the Egyptians themselves, who were destined to drown in that very same sea without a single survivor [קאסוטו, פענח רזא].

The clearing of the land was absolute, ensuring that not a single insect remained. The eradication was so thorough that even the locusts the Egyptians had already caught, salted, and stored for food miraculously returned to life and flew into the sea. Pharaoh had hoped to retain at least these preserved insects as a small compensation for his ruined crops, but God ensured the Egyptians would derive absolutely no benefit or pleasure from the plague [רש״י, גור אריה, מלבי״ם, משכיל לדוד].

The primary approach among commentators distinguishes between two categories of plagues to explain this total removal. Plagues that were newly created specifically as punishments, such as the frogs and lice, simply died where they were when the affliction ended. However, plagues composed of existing creatures brought into Egypt, like the wild beasts and the locusts, were entirely removed so the Egyptians could not harvest their hides or meat for personal gain [בכור שור, הדר זקנים, הטור הארוך].

The complete departure of the locusts also carries a deeper symbolism, hinting at the future exodus of the Israelites. Just as the locusts vanished without a trace, the Israelites would eventually leave Egypt entirely, leaving nothing behind and even carrying the bones of their ancestors with them [שפתי כהן].

Finally, the total removal of the swarm from the Egyptian borders established a lasting historical reality. Because of Moses's prayer, locusts would never again destroy the crops of Egypt. Even if modern swarms invade neighboring lands and cross the border, they do not consume Egyptian produce. This stands in sharp contrast to the plague of frogs, where Moses prayed that they remain in the Nile, leaving behind a dangerous predator as a permanent reminder, whereas the locusts were erased from the land forever [רבנו בחיי, רבנו חננאל, תולדות יצחק].