Exodus 11:1
And the LORD said unto Moses, Yet will I bring one plague more upon Pharaoh, and upon Egypt; afterwards he will let you go hence: when he shall let you go, he shall surely thrust you out hence altogether. And the LORD said unto Moses, Yet will I bring one plague more upon Pharaoh, and upon Egypt; afterwards he will let you go hence: when he shall let you go, he shall surely thrust you out hence altogether.
God announced one more plague to come upon Pharaoh and upon Egypt, and this was to be the final plague, His last judgment before Israel's release. Moses still had this message from God to carry to Pharaoh even after Pharaoh had threatened him with death if he appeared before him again. He entered Pharaoh's presence fearlessly to speak it. After that plague Pharaoh would let Israel go hence, bringing their release. When he let them go he would not merely permit departure but would surely thrust them out hence altogether, forcefully driving them out.
The plagues exposed the powerlessness of Egypt's idols. They showed that Jehovah alone is God. The final judgment made plain to all His authority as the one who executes judgment on the earth.