Rashi on Exodus 6:27/רש"י על שמות ו׳:כ״ז

1הם המדברים וגו׳ THESE ARE THEY WHO SPAKE TO PHARAOH — It was they who received the command to speak to Pharaoh (cf. v. 26), and it was they who carried it out by actually speaking to him (cf. e.g. Exodus 7:7).

2הוא משה ואהרן THESE ARE MOSES AND AARON — they remained always the same in carrying out their mission and in their integrity from beginning to end (cf. Megillah 11a).