Moses receives a revelation from God while tending his flock near Mount Sinai. God speaks to Moses from a burning bush and commands him to go to Pharaoh and demand that he free the Israelites from slavery in Egypt. God gives Moses signs to demonstrate his divine authority, including turning his staff into a snake and curing his hand of leprosy. Moses requests that his brother Aaron accompany him to speak on his behalf since he has a speech impediment, and God agrees.