Now Joseph had been brought down to Egypt, and Potiphar, an officer of Pharaoh, the captain of the guard, an Egyptian, had bought him from the Ishmaelites who had brought him down there.
Joseph’s brothers had sold him to a caravan of Ishmaelites who were on their way to Egypt. When the Ishmaelites reached Egypt they sold Joseph to Potiphar. We are told two things about him: he was the captain of Pharaoh’s guard and he was an Egyptian. Saying he was captain of the guard makes sense. It gives us some information about who Potiphar was. But saying he was an Egyptian seems redundant. He lived in Egypt and was an officer of Pharaoh. What could he be except an Egyptian?