The Israelites had so many children that the Egyptian Pharaoh ordered the Israelite baby boys to be killed. One Israelite mother put her baby boy into a basket-boat in the river. The baby was found by the daughter of Pharaoh. She thought the water god had sent the baby boy to her. Pharaoh's daughter named the baby “Moses” because she drew him out of the water. She loved the baby boy. Moses was reared in Pharaoh's house as her son.
Then the Egyptians made the Israelites work harder. Later, the Israelites cried out to God for help. God sent Moses to lead the Israelites out of Egypt.
God, through Moses and Aaron his brother, did very powerful, frightening and destructive things to the Egyptians because Pharaoh refused to let them go.
At God's command, Moses told Aaron to strike the water with his rod and God changed the water in the Nile river into blood. God also caused the land to be covered with frogs and did many other things through Moses. Then, when Pharaoh would still not let the Israelite people go, God caused the part of the country where the Egyptians lived to turn into thick darkness—like black fog. They could not see anything but the Israelites still had light.
Pharaoh still would not let the Israelites go and he made them work even harder.
Finally, Moses told Pharaoh, “God is going to kill all the Egyptian firstborn—man and beast. You will never see my face ever again,” and he left.
Then God told Moses to tell the Israelites to sacrifice a lamb and put the blood on the two side doorposts and the top of the doorway of their houses. They were not to go out of their house until morning. God would pass over their houses and not allow the destroyer to kill their firstborn in the houses marked with blood on the doorway.
God called this night the Passover. At midnight God killed all the firstborn Egyptian of men and animals. As the Egyptians cried loudly, Pharaoh told the Israelites they could leave. Remember, Pharaoh had Israelite babies and children killed. So as punishment, God judged the Egyptians for killing the Israelite children by killing their firstborn.