Exodus 4 - 6

Moses really didn't want to go back to Egypt to face his past and embrace what God was asking him to do. He was arguing with God about it, so God started showing him the power available to him from above. Moses throws down his walking stick and it becomes a snake in an instant, scaring Moses so badly, he runs from it. Then God tells him to grab hold of it, which Moses does, and it turns back to a stick. God gives Moses two other examples of miracles God has enabled him to perform in order to make the people know he has been sent by God to lead them.
Then he starts in saying he is not an eloquent talker and he thinks that will disqualify him from the task, but God reminds him who gave him speech in the first place. Moses still resists and God becomes angry, but His anger is tempered with grace, as it always is, and He tells Moses to take his brother, Aaron, who is well spoken. In fact, God has already spoken to Aaron, and Aaron is on his way out to the desert to meet Moses. Moses is still tentative about going to lead the Israelites out of Egypt, but he goes back to his father-in-law to ask his leave to go "visit" his family. No mention is made of what God had commissioned him to do. Jethro gave his blessing, so Moses loaded up his wife and sons on a donkey and set out.
Apparently, God had spoken with Moses about circumcising his sons but Moses had never done it. It had to be done before they joined the Israelite tribes, or they would not be accepted, so God got very angry with Moses and was about to kill him. Also apparent from the text, Moses' wife, Zipporah, didn't agree with the circumcision ritual, but to save her husband’s life, she quickly took a knife and did the surgeries, but she was mad about it, calling Moses a “bloody husband,” while throwing the foreskins at his feet.
Aaron and Moses meet along the trail at the very same mountain where Moses saw the burning bush, Mt. Horeb, which they now called The Mountain of God. (My son has been to this mountain!) Here Moses told Aaron what their task was to be and they both returned to Egypt, where Moses, indeed, had Aaron do the talking to the elders while he performed all the miracles God had given him to cause them to believe them. The Hebrews were very touched when they learned that God knew of their misery and was concerned for them after all, so they worshipped Him.
Chapter 5 begins the saga of Moses and Aaron speaking to Pharaoh and asking permission for the Israelis to leave Egypt and Pharaoh refusing. Pharaoh did not know the God of whom they spoke, so he had no regard for Him. He gave orders for the Hebrews to be oppressed even more. The leaders of the Hebrews appeal personally to Pharaoh, and are rebuffed. They blame Moses and Aaron for getting them in trouble with Pharaoh. Therefore, Moses goes back to God and complains of the treatment they received.
God reminds Moses of the covenant He made with Abraham, Isaac and Jacob to give them the land of Canaan, and of his intention to keep that covenant. He tells Moses to get back to Pharaoh and demand the release of the Hebrews. Moses again argues with God, reminding Him of his speech impairment. So God calls Aaron to meet with them and commissions them both to go lead the people out of slavery in Egypt.
There follows a short genealogy of Moses and Aaron’s family to show they were from the tribe of Levi, and chosen by God to be priests and leaders of Israel.