As the story goes, Moses was born in Egypt, probably in the 13th century BCE, at a time when Hebrews — in slavery for centuries — were required, by order of the Pharaoh, to drown their male babies in the Nile at birth. His mother instead set him adrift on the river in a papyrus basket, and he was rescued by the Pharaoh’s daughter, who raised him in the palace as if he were her son, naming him Moses.
Here’s the story as told by an old illustration caption:
Moses’s mother Jochebed kept him hidden for three months to avoid having to drown him in the Nile River as the Pharaoh — perhaps Thutmose III — required for all newborn Hebrew boys. When she could no longer keep the baby concealed, she set him in the Nile in an “ark of bulrushes … daubed with slime and with pitch.” The Pharaoh’s daughter was bathing downstream, and, glimpsing the little boat, had her servant fetch it. The baby inside was crying, and she felt compassion for him. Miriam, Moses’s sister, had been watching the basket’s progress from a nearby hiding place. When she saw that the Pharaoh’s daughter felt tenderly toward the baby, Miriam offered to find a Hebrew nursemaid for him. Thus, the Pharoah’s daughter unknowingly ended up paying Moses’s own mother, Jochebed, to nurse him until he was big enough to be raised as the Pharoah’s daughter’s own son. Perhaps young Moses was a friend to the future Pharoah — likely Amenhotep III — to whom he would later deliver Yahweh’s command: “Let my people go.”
As an adult, Moses killed an Egyptian whom he saw beating a Hebrew slave, and then fled for his life to the Arabian town of Midian. There, he married a priest’s daughter and worked for many years as a shepherd.
At this time, the Hebrew god Yahweh (Yahweh, Jehovah, God) had been absent from his people, the Israelites, for hundreds of years. Moses was tending his sheep in the desert near “the mountain of God” when Yahweh appeared to him in a burning bush.
Exodus 3:1 Now Moses kept the flock of Jethro his father-in-law, the priest of Mid’i-an: and he led the flock to the back side of the desert, and came to the mountain of God, even to Horeb.
2 And the angel of the Lord appeared unto him in a flame of fire out of the midst of a bush: and he looked, and, behold, the bush burned with fire, and the bush was not consumed.
Yahweh (or his angel) told Moses his mission from God was to go back to Egypt, free the Hebrew slaves, and lead them to the promised land, Canaan, which was already occupied by numerous tribes.
Exodus 3:8 and I am come down to deliver them out of the hand of the Egyptians, and to bring them up out of that land unto a good land and a large, unto a land flowing with milk and honey; unto the place of the Canaanites, and the Hittites, and the Amorites, and the Per’izzites, and the Hivites, and the Jeb’usites.
Moses was not interested in fulfilling this mission; he explained that he wasn’t eloquent enough, and that no one would ever believe Yahweh had appeared to him. The god told him that Moses’s brother Aaron was a good speaker and would help out, and that Yahweh himself would put the right words in Moses’s mouth. He also provided Moses with a rod that turned into a serpent and a couple of extra miracles to use if needed—an appearing/disappearing leprosy and the ability to turn river water into blood:
Exodus 4:1 And Moses answered and said, But, behold, they will not believe me, nor hearken unto my voice: for they will say, The Lord hath not appeared unto thee.
2 And the Lord said unto him, What is that in thine hand? And he said, A rod.
3 And He said, Cast it on the ground. And he cast it on the ground, and it became a serpent; and Moses fled from before it.
4 And the Lord said unto Moses, Put forth thine hand, and take it by the tail. And he put forth his hand, and caught it, and it became a rod in his hand:
5 that they may believe that the Lord God of their fathers, the God of Abraham, the God of Isaac, and the God of Jacob, hath appeared unto thee.
6 And the Lord said furthermore unto him, Put now thine hand into thy bosom. And he put his hand into his bosom: and when he took it out, behold, his hand was leprous as snow.
7 And he said, Put thine hand into thy bosom again. And he put his hand into his bosom again; and plucked it out of his bosom, and, behold, it was turned again as his other flesh.
8 And it shall come to pass, if they will not believe thee, neither hearken to the voice of the first sign, that they will believe the voice of the latter sign.
9 And it shall come to pass, if they will not believe also these two signs, neither hearken unto thy voice, that thou shalt take of the water of the river, and pour it upon the dry land: and the water which thou takest out of the river shall become blood upon the dry land.
Moses really, really did not want to go back to Egypt, and he told Yahweh to please choose someone else. The god became angry and told him to just do it. He told Moses that all the people who had been after him for the murder he had committed were dead now. So Moses, along with Aaron, went to Egypt and organized the Hebrew slaves, and then went before the Pharaoh to demand the slaves’ release.