Moses first encountered God at the burning bush while tending the flock of his father-in-law near Horeb, the mountain of God. There God commissioned him to return to Egypt and lead the Israelites from slavery.
After the Exodus, Israel arrived at the wilderness of Sinai and encamped before the mountain. God descended upon Sinai amid thunder, lightning, cloud, fire, smoke, and the sound of a trumpet.
At Sinai God gave Israel the Ten Commandments and established the covenant with the nation. Moses repeatedly ascended the mountain and received laws and instructions concerning worship, the tabernacle, priesthood, and Israel's covenant responsibilities.
The golden calf episode occurred while Moses was on the mountain. After interceding for Israel, Moses received a renewed set of tablets before the people eventually departed from Sinai toward the Promised Land.