Exodus 10:6
And they shall fill thy houses, and the houses of all thy servants, and the houses of all the Egyptians; which neither thy fathers, nor thy fathers’ fathers have seen, since the day that they were upon the earth unto this day. And he turned himself, and went out from Pharaoh.
Cross-reference
Exodus 10:14 records the fulfillment of this warning — locusts came exactly as described, with unprecedented severity.
Exodus 10:15 describes the locusts covering the land and devouring all vegetation — the direct outcome of the warning given here.
Exodus 8:3 records the same pattern with frogs: they too filled houses — connecting the locust plague to earlier infestation miracles.
In Exodus 8:21, the plague of flies similarly fills houses — showing a recurring pattern of domestic infestation across plagues.
Exodus 11:8 contains another warning from Moses — the prediction of the firstborn's death — following the same pattern of prophetic announcement seen here.
Joel 2:2 echoes this same claim of unprecedentedness for a locust plague — 'like none ever before' — reinforcing the eschatological pattern.