Or HaChaim on Exodus 4:27/אור החיים על שמות ד׳:כ״ז

1 לך לקראת משה, "go towards Moses, etc!" Although we have heard G'd say to Moses already in 4,14 that his brother Aaron was on his way to meet him, the actual instruction to Aaron came from G'd while Aaron was still in Egypt. There is no question that the prophecy in this verse was adressed directly to Aaron even though we learned in Torat Kohanim 1 that wherever the Torah writes: "G'd spoke to Moses and Aaron," that the directive was spoken to Moses only and he in turn was to convey it to Aaron, this does not apply here. Even according to the view of Rabbi Yossi Haglili who excludes Aaron from receiving a communication from G'd directly even while both were in Egypt, he referred only to communications which concerned an independent mission to outsiders. There is no reason to believe that G'd did not speak to Aaron directly concerning what Aaron himself was to do. Our verse proves that Aaron was a prophet in his own right.