month, slaughter it on the 14th, and daub its blood on their doorposts and lintels, and to observe the Passover meal that night, the night of the full moon. In the final plague, Yahweh kills all the firstborn sons of Egypt and the firstborn cattle, but the Israelites, with blood on their doorposts, are spared. Yahweh commands that the Israelites observe a festival as "a perpetual ordinance" to remember this event (Exodus 12:14). Pharaoh finally casts the Israelites out of Egypt after his firstborn son is killed. Yahweh leads the Israelites in the form of a pillar of cloud in the day and a pillar of fire at night. However, once the Israelites have left, Yahweh "hardens" Pharaoh's heart. Pharaoh then changes his mind and pursues the Israelites to the shore of the Red Sea. Moses uses his staff to part the Red Sea, and the Israelites cross on dry ground, but the sea closes down on the pursuing Egyptians, drowning them all. The Israelites begin to complain, and Yahweh miraculously provides them with water and food, eventually raining manna down for them to eat. The Amalekites attack at Rephidim, but are defeated. Jethro (Moses' father-in-law) convinces Moses to appoint judges for the tribes of Israel. The Israelites reach the Sinai Desert and Yahweh calls Moses to Mount Sinai, where Yahweh reveals himself to his people and establishes the Ten Commandments and Mosaic covenant: the Israelites are to keep his torah (i.e. law, instruction), and in return he will give them the land of Canaan. Yahweh establishes the Aaronic priesthood and various rules for ritual worship, among other laws. However, in Moses's absence the Israelites sin against Yahweh by creating the idol of a golden calf, and as retaliation Yahweh has the Levites kill three thousand people (Exodus 32:28), and Yahweh sends a plague on the Israelites. The Israelites now accept the covenant, which is reestablished, build a tabernacle for Yahweh, and receive their laws. Yahweh commands Moses to take a census of the Israelites and establishes the duties of the Levites. Then the Israelites depart from Mount Sinai. Yahweh commands Moses to send twelve spies ahead to Canaan to scout the land. The spies discover that the Canaanites are strong, and, believing that the Israelites cannot defeat them, the spies falsely report to the Israelites that Canaan is full of giants so that the Israelites will not invade (Numbers