Ten national disasters:
- the main source of water (the Nile) became undrinkable for seven days
- frogs everywhere
- a plague of gnats or lice (with no warning to Pharaoh beforehand)
- a plague of flies or beetles
- Egyptian livestock die suddenly
- boils afflict the Egyptians (without a warning beforehand)
- a massive lightning and hailstorm
- a plague of locusts that takes everything left after the hailstorm
- darkness until Pharaoh asked for Moses to intervene (with no warning to Pharaoh before the ‘plague’ struck)
- death of the firstborn.
The first plague resolved itself as it lasted for only seven days. The second plague (of frogs) must have lasted longer than that as Pharaoh asked Moses to make it stop, thereby establishing a pattern of bargaining with God (through Moses) then reneging.
Pharaoh’s servants were more reasonable, taking action to protect themselves from the plagues as best they could.
So what was God’s aim in all this? Each of the plagues takes on a specific Egyptian God, and the aim was for God to show who really is God. In His own words to the Egyptians:
Exodus 9:15-16 By now I could have lifted my hand and struck you and your people with a plague to wipe you off the face of the earth. But I have spared you for a purpose—to show you my power and to spread my fame throughout the earth.
This might appear strange to our modern view of things, but neither the Israelites nor the Egyptians remembered who God was before Moses returned from his time in the Midian desert. Remember, Pharaoh’s initial response at his first meeting with Moses (and before any plague), was less than respectful:
Exodus 5:2 … And who is the Lord? Why should I listen to him and let Israel go? I don’t know the Lord, and I will not let Israel go.
Concrete object lessons seem to be the way God taught at the time.