Exodus 10 - 12

"How long will you refuse to humble yourself before me?" is what God then had Aaron and Moses ask of Pharaoh, and this is the question he asks all persistent unbelievers. Pharaoh's officials even urged him to let the Israelites go at that time, and he listened, somewhat. Pharaoh is still trying to bargain with God. He calls Moses and Aaron in to tell them the men can go, but the Hebrew women and children must stay in Egypt. So begins the plague of locusts.
Locusts are an insect similar to a grasshopper. Here in Wyoming, we know what grasshoppers are all about. They are about eating every blade of grass and shrub they can, and when that is gone, they begin to eat fence posts, houses, trees, etc. I have even seen them eat each other. They were so thick one year, one would squish them on the roads as the vehicles rolled over them, and then their relatives would descend on the dead bodies to snack. This is what God sent upon Egypt. This time it says Pharaoh quickly summoned Moses to pray for deliverance from the locusts. He did not want to think about it for a day--he wanted it immediately. As quickly as they were gone, he again changed his mind, refusing to let the people go.
Then the sky turned dark and it says that Egypt was plunged into pitch-blackness for three days, except in the Land of Goshen where the Hebrews lived. People could not even go about it was so dark, so Pharaoh again relents a little. This time he said all the people could leave, but they were to leave their livestock there. God said, "No deal," and Pharaoh threatened Moses and Aaron's lives. Therefore, God had to take drastic measures.
God never brings calamity on us without warning. Moses warned Pharaoh that God was about to kill all the firstborn children and livestock in Egypt. God already knew Pharaoh would not listen to Moses in spite of all the plagues that had come upon him.
God then gave instructions for the “Passover” to the Israelites. They were to sacrifice yearling sheep or goats that had no defects according to how many people there were in the household. The blood of the animals was to be painted over their doorposts and they were to roast and eat the meat standing up, ready to be on the march.
The blood was a sign to the Angel of the Lord that the household believed in Him to save them. The Angel would "pass over" the house and not kill the firstborn. Then God instructed the Hebrews to commemorate the event later as the Feast of the Unleavened Bread. They were not to eat any raised bread or even have any yeast in their houses for seven days prior. Yeast is likened in the Bible to sin. "A little leaven leavens the whole lump," just like a little sin creeps into all areas of our lives.
So Moses relayed the instructions on to all the Hebrews, who followed them to the letter. That night, all the firstborn children and animals in Egypt, except those protected by blood on the doorposts, were killed. The Bible says there was loud wailing in Egypt, for there was not a house without someone dead.
Some people say, "How could a loving God do such a thing?" Well, we all have to die sometime. These children were better off because they would have lived Godless lives, died eventually and went to Hell. Instead, God took them to heaven. That is where all innocent children go if they die before they reach the age of knowing. Sometimes God has to do drastic things to get us to listen and acknowledge Him as God.
That very night, Pharaoh told Moses and Aaron to leave Egypt and take all their people and all their possessions. And he asked them to pray for him.
Hurriedly, the Hebrews gathered their things and prepared to march. God even caused the Egyptians to load them down with gold and silver and clothing on their way out. There was more than a half-million men alone in the Hebrew contingent as they left Egypt. How the tribes had multiplied in 430 years of living in isolation in Egypt. As they were on their way out, God gave them further instructions on how they were to memorialize the event for centuries to come.