Rashi on Deuteronomy 17:9/רש"י על דברים י״ז:ט׳

1הכהנים הלוים [AND THOU SHALT COME UNTO] THE PRIESTS THE LEVITES — i.e. unto the priests, who descend from of the tribe of Levi.

2ואל השפט אשר יהיה בימים ההם [AND THOU SHALT COME UNTO THE PRIESTS …] AND UNTO THE JUDGE THAT SHALL BE IN THOSE DAYS — The last apparently redundant words suggest: and even though he is not as eminent as other judges that have been before him, you must obey him — you have none else but the judge that lives in your days (i.e. you are only concerned with him) (Rosh Hashanah 25b).