What Does Exodus 10:19 Mean?

And the LORD turned the wind into a very strong west wind, which lifted the locusts and drove them into the Red Sea. Not a single Locust was left in all the country of Egypt. The locust removal mirrors the locust delivery: just as an east wind brought the locusts in (verse 13), a west wind (literally "sea wind": the Mediterranean wind) removes them.

The meteorological reversal, east wind brings, west wind takes, is a natural process directed by divine will at the timing of Moses' prayer. The wind that delivers the plague is directly reversed by the wind that removes it, with no natural transition period: the locusts came at an announced hour the east wind delivered; the locusts leave at Moses' prayer via a YHWH-directed west wind.

The "drove them into the Red Sea" (Hebrew: Yam Suf, the Sea of Reeds: the same body of water that will drown Pharaoh's army in Exodus 14-15) is the first mention of the Red Sea in Exodus: introduced as the destination of the locust swarm. YHWH deposits the locusts in the same body of water he will use to eliminate the Egyptian military. The Red Sea appears first as the locusts' grave; it will appear conclusively as Pharaoh's army's grave. The narrative geography connects the locust removal and the Exodus crossing: both go into the Yam Suf, both by YHWH's action at Moses' involvement.

"Not a single locust was left in all the country of Egypt" mirrors the livestock plague's "not one Israelite animal died" and the fly removal's "not one remained." The totality of the removal, not one locust left, answers the totality of the infestation: not a green thing remained. YHWH sends comprehensively and removes comprehensively. The complete removal of the eighth plague is as much a demonstration of divine power as the complete sending: other locust swarms dissipate gradually over areas; this one is removed entirely in response to prayer, all at once, into the sea.