The Plagues of Egypt (Hebrew: מכות מצרים, Makot Mitzrayim), also called the ten biblical plagues, were ten calamities that, according to the biblical Book of Exodus, God inflicted upon Egypt as a demonstration of power, after which the Pharaoh conceded to Moses' demands to let the enslaved Israelites go into the wilderness to make sacrifices. God repeatedly hardened the Pharaoh's heart to prevent him from consenting until after the tenth plague. The Israelites' eventual departure began the Exodus of the Hebrew people.
The plagues served to contrast the power of the God of Israel with the Egyptian gods, invalidating them. Some commentators have associated several of the plagues with judgment on specific gods associated with the Nile, fertility and natural phenomena. According to Exodus 12:12, all the gods of Egypt would be judged through the tenth and final plague: "On that same night I will pass through Egypt and strike down every firstborn of both people and animals, and I will bring judgment on all the gods of Egypt. I am the LORD."
The reason for the plagues appears to be twofold: to answer Pharaoh's taunt, "Who the LORD, that I should obey his voice to let Israel go?", and to indelibly impress the Israelites with God's power as an object lesson for all time, which was also meant to become known "throughout the world".
According to the Book of Exodus, God hardened Pharaoh's heart so he would be strong enough to persist in his unwillingness to release the people, so that God could manifest his great power and cause his power to be declared among the nations, so that other people would discuss it for generations afterward. In this view, the plagues were punishment for the Egyptians' long abuse of the Israelites, as well as proof that the gods of Egypt were false and powerless. If God triumphed over the gods of Egypt, a world power at that time, then the people of God would be strengthened in their faith, although they were a small people, and would not be tempted to follow the deities that God proved false. Exodus 9:15–16 (JPS Tanakh) portrays Yahweh explaining why he did not accomplish the freedom of the Israelites immediately: "I could have stretched forth My hand and stricken you and your people with pestilence, and you would have been effaced from the earth. Nevertheless I have spared you for this purpose: in order to show you My power and in order that My fame may resound throughout the world."
The plagues seemed to affect "all the land of Egypt", but the children of Israel were unaffected. For the last plague, the Torah indicates that they were only spared from the final plague by sacrificing the Paschal lamb, marking their place directly above their doors with the lamb's blood, and hastily eating the roasted sacrifice together with unleavened bread (now known as Matzoh) which they took from their ovens in haste, as they made ready for the Exodus. The Torah describes God as actually passing through Egypt to kill all firstborn children and cattle, but passing over (hence "Passover") houses which have the sign of lambs' blood on the doorpost. It is debated whether it was actually God who came through the streets or one of his angels. Some also think it may be the Holy Spirit. It is most commonly known as the "Angel of Death". The night of this plague, Pharaoh finally relents and sends the Israelites away under their terms.
After the Israelites leave en masse, a departure known as The Exodus, God introduces himself by name and makes an exclusive covenant with the Israelites on the basis of this miraculous deliverance. The Ten Commandments encapsulate the terms of this covenant. Joshua, the successor to Moses, reminds the people of their deliverance through the plagues. According to 1 Samuel, the Philistines also knew of the plagues and feared their author. Later, the psalmist sang of these events.
The Torah also relates God's instructions to Moses that the exodus of the Israelites from Egypt must be celebrated yearly on the holiday of Passover (Pesaḥ פסח); the rituals observed on Passover recall the events surrounding the exodus from Egypt. The month of Nisan has become important to the Jews. The Torah additionally cites God's sparing of the Israelite firstborn as a rationale for the commandment of the redemption of the firstborn. This event is also commemorated by the Fast of the Firstborn on the day preceding Passover but which is traditionally not observed because a siyum celebration is held which obviates the need for a fast.