When God sent Moses to lead the Israelites out of Egypt, He told Moses: “When Pharaoh does not listen to you, then I will lay My hand on Egypt and bring out My hosts, My people the sons of Israel, from the land of Egypt by great judgments. The Egyptians shall know that I am the LORD, when I stretch out My hand on Egypt and bring out the sons of Israel from their midst.” (Ex. 7:4-5 New American Standard) These judgments were the ten plagues God brought upon Egypt to force Israel’s release.
The first three plagues affected both the Egyptians and the Israelites: (1) turning the water of the Nile river into blood (Ex. 7:17-22); (2) plague of frogs (Ex. 8:2-7); (3) plague of gnats (Ex. 8:16-19). Plagues four through nine affected only the Egyptians. “But on that day I will set apart the land of Goshen, where My people are living, so that no swarms of flies will be there, in order that you may know that I, the LORD, am in the midst of the land” (Ex. 8:22-23 NASB).The next five plagues were: (4) swarm of flies (Ex. 8:21-24); (5) pestilence on the livestock (Ex. 9:2-7); (6) boils (Ex. 9:8-12); (7) hail and fire (Ex. 9:18-26); (8) locusts (Ex. 10:3-11); (9) three days of darkness.—Ex. 10:21-24
After each of the first nine plagues was lifted, Pharaoh refused to let the Israelites go. Therefore, “the LORD said to Moses, ‘One more plague I will bring on Pharaoh and on Egypt; after that he will let you go from here. … About midnight I am going out into the midst of Egypt, and all the firstborn in the land of Egypt shall die, from the firstborn of the Pharaoh who sits on his throne, even to the firstborn of the slave girl who is behind the millstones; all the firstborn of the cattle as well.”—Exod. 11:1,4,5 (NASB).
To protect the first-born Israelites, God instructed each family to select a male lamb without blemish, kill it, sprinkle its blood on the lintels and sideposts of the doors and eat the rest of the lamb roasted by fire that same night. (Ex. 12:1-33) This ceremony, known by the Jews as the Passover, saved the Israelite first-born while the first-born Egyptians died. This plague forced Pharaoh and the Egyptians to let the Israelites go free lest “We be all dead men.”—Ex. 12:33 (NASB)