Albert Barnes Commentary Exodus 6:26-27

"These are that Aaron and Moses, to whom Jehovah said, Bring out the children of Israel from the land of Egypt according to their hosts. These are they that spake to Pharaoh king of Egypt, to bring out the children of Israel from Egypt: these are that Moses and Aaron." — Exodus 6:26-27 (ASV)

This emphatic repetition shows the reason for inserting the genealogy. The names of Moses and Aaron are given twice and in a different order; used in (Exodus 6:26) probably to mark Aaron as the older in the genealogy, and used in (Exodus 6:27) to denote the leadership of Moses.