Then Moses went up the mountain to God, and the Lord called to him from the mountain, “This is what you must say to the descendants of Jacob. Tell the Israelites,
Moses was taking care of the sheep of his father-in-law Jethro, the priest of Midian. As he led the sheep to the far side of the desert, he came to Horeb, the mountain of God.
The Lord would speak to Moses personally, as a man speaks to his friend. Then Moses would come back to the camp, but his assistant, Joshua, son of Nun, stayed inside the tent.