The Book of Exodus begins more than four hundred years after Joseph, his brothers, and the Pharaoh he once served have all died. The new leadership in Egypt—feeling threatened by Jacob's descendants, who have increased greatly in size—embarks on a campaign to subdue the Israelites, forcing them into slavery and eventually decreeing that all Hebrew boys must be killed at birth in the Nile River. The Hebrew women resist the decree, and one woman opts to save her newborn son by setting him afloat on the river in a papyrus basket. Fortunately, Pharaoh's daughter discovers the abandoned child and raises him after he has been nursed, naming him Moses.
Moses is aware of his Hebrew roots, and, one day, he kills an Egyptian who is beating an Israelite worker. Moses flees in fear to Midian, a town near Sinai, where he meets a priest named Jethro and marries the man's daughter, beginning a new life as a shepherd. God, however, is concerned for the suffering of the Israelites, and He appears to Moses in the form of a burning bush. God speaks to Moses, informing him of His plan to return the Israelites to Canaan—to "a land flowing with milk and honey" (3:8)—and to send Moses back to Egypt to accomplish this task. Moses is timid and resists, citing his lack of eloquence and abilities, and refuses to go. God is angered but encourages Moses, presenting him with a staff for performing miracles and instructing Moses to take his brother, Aaron, with him as an aid. When Moses asks God what His name is, God replies, "I AM WHO I AM" (3:14).
Moses and Aaron return to Egypt, where Moses organizes the Israelites and confronts the Pharaoh, demanding the release of the Hebrew people. Moses performs a miracle, turning his staff into a snake, but Pharaoh is unimpressed and only increases the workload for the Israelites. God responds by inflicting a series of ten plagues on Egypt. God turns the Nile River into blood, causes frogs to cover Egypt, turns all of the dust in Egypt to gnats, and causes swarms of flies to come into the houses of Pharaoh and his officials. God then strikes Egypt's livestock with a disease, creates festering boils on humans and animals, and sends thunder, hail, and fire that destroy crops, livestock, and people. God sends swarms of locusts, and covers Egypt with "a darkness that can be felt" (10:21). Before each plague, Moses demands the Israelites' release, and after each plague, God purposefully "hardens" Pharaoh so that he refuses the request (4:21, 7:22). The tenth and final plague kills all the firstborn males in Egypt. Before the plague, Moses instructs the Hebrew people to cover their door posts in the blood of a sacrificed lamb as a sign for God to protect their homes from His killings. Pharaoh relents and releases the more than 600,000 Israelites who, in turn, plunder the Egyptians' wealth. Upon leaving, Moses enjoins the Israelites to commemorate this day forever by dedicating their firstborn children to God and by celebrating the festival of Passover, named for God's protection from the final plague (12:14–43).
Guided by a pillar of cloud during the day and by fire during the night, Moses and the Israelites head west toward the sea. Pharaoh chases them. The Israelites complain that Moses has taken them to die in the wilderness, and Moses, at God's bidding, parts the sea for the people to cross. Pharaoh follows and Moses closes the waters back again, drowning the Egyptian army. Witnessing the miracle, the people decide to trust Moses, and they sing a song extolling God as a great but loving Warrior. Their optimism is brief, and the people soon begin to worry about the shortage of food and water. God responds by sending the people food from heaven, providing a daily supply of quail and a sweet bread-like substance called manna. The people are required only to obey God's commandments to enjoy this food. Soon thereafter, the Israelites confront the warring Amalekite people, and God gives the Israelites the power to defeat them. During battle, whenever Moses raises his arms, the Israelites are able to rout their opponents.
Three months after the flight from Egypt, Moses and the Israelites arrive at Mount Sinai, where God appears before them, descending on the mountain in a cloud of thunder and lightning. Moses climbs the mountain, and God gives Moses two stone tablets with Ten Commandments inscribed on them regarding general, ethical behavior as well as an extended series of laws regarding worship, sacrifices, social justice, and personal property. God explains to Moses that if the people will obey these regulations, He will keep His covenant with Israel and will go with them to retrieve from the Canaanites the land promised to Abraham. Moses descends from the mountain and relates God's commandments to the people. The people agree to obey, and Moses sprinkles the people with blood as a sign of the covenant. Moses ascends to the mountain again where God gives him more instructions, this time specifying in great detail how to build a portable temple called an ark in which God's presence will dwell among the Israelites. God also emphasizes the importance of observing the Sabbath day of holy rest.
Moses comes down from the mountain after forty days, only to find that Aaron and the Israelites have now erected an idol—a golden calf that they are worshipping in revelry, in direct defiance of the Ten Commandments. Moses breaks the stone tablets on which God has inscribed the new laws, and God plans to destroy the people. Moses intercedes on the Israelites' behalf, begging God to relent and to remember His covenant. Pleased with Moses, God is appeased and continues to meet with Moses face to face, "as one speaks to a friend," in a special tent set aside for worship (33:11). God reaffirms His covenant with Moses, and, fashioning new stone tablets to record His decrees, God declares Himself to be a compassionate, loving, and patient God. At Moses's direction, the Israelites renew their commitment to the covenant by erecting a tabernacle to God according to the exact specifications God has outlined.