But I will harden Pharaoh's heart,
Miraculous signs and wonders will be displayed, but it will take God's hand and mighty acts of judgment before the Israelites will be able to leave Egypt. Yet God will bring His people (whom he refers to as 'my divisions', which is a very military image) out of Egypt in the end.
Moses and Aaron obey what the LORD commands them to do. The text notes that Moses is eighty years old, while his brother Aaron is eighty-three, when this whole adventure begins. That makes me laugh, to think that God will take these older men and bring them into the most important task of their lifetimes when they are in their eighties. I think it is wonderful. It shows that it is the LORD, not our own strength or abilities, which allows us to accomplish anything. I also note that it is their obedience to the LORD which sets this plan into motion. However, it is very clear that it is the LORD who will accomplish the task of bring the Israelites out of Egypt, as He had promised.