Aharon the unchanging "stander" elevated

ברש"י להגיד שבחו של אהרן שלא שינה פרשנו שלעולם עשה כן בלי השתנות דאדם נקרא מהלך שבא מעט מעט אל השלימות.

Rashi states: "to tell the praise of Aharon, that he did not change" - we explain that he always acted thus without any change; for a person is called a "walker" (mehalech), who comes little by little toward perfection.

An ordinary man advances gradually, step by step - he is a "mover," constantly in process toward wholeness.

אבל אהרן הכהן מלאך ה' צבאות הוא שנקרא עומד.

But Aharon the Kohen is "an angel of Hashem of Hosts" (Malachi 2:7), who is called "one who stands" (omeid).

Aharon had reached the steadfast, fixed level of an angel - an "omeid," already standing in his fullness rather than still climbing.

וכ"כ ונתתי לך מהלכים כו' העומדים.

And so it is written: "and I will give you mahlechim (movers / a place to walk) among these that stand" (Zechariah 3:7).

The posuk, addressed to the Kohen Gadol, contrasts those who "move" with the "standers" - the angels.

ואמת [*כי] נתעלה ע"י עבודת המקדש וזהו שרמזו חז"ל מעלה הי' שעלי' הכהן עומד.

And it is true that he was elevated through the avodah of the Mikdash - and this is what Chazal hinted: "there was a step (ma'alah) upon which the kohen stood."

The physical "step" on which the kohen stood to kindle the menorah hints at the spiritual elevation (ma'alah) he attained through the avodah.

פי' בהעלותך ממש.

Meaning: "Beha'alosecha" - literally "when you raise up."

The parsha's word "Beha'alosecha" (kindling, lit. "raising up" the lamps) is taken in its plain sense of elevation.

את הנרות באמצעות הנרות נתעלה.

"The lamps" - by means of the lamps he was elevated.

Through kindling the menorah's lights, Aharon himself was raised up to his exalted standing.

ואז אל מול כו' יאירו וע"ז כתיב כן עשה שנתעלה כו':

And then "toward the face [of the menorah]… they shall give light" (Bamidbar 8:2), and about this it is written, "so he did" (Bamidbar 8:3) - that he was elevated.

The lamps shining "toward the face" reflect Aharon's own elevation; "so he did" testifies that through this avodah he was lifted to that steadfast level.

Summary: While an ordinary person is a "mover" who advances toward perfection little by little, Aharon attained the angelic level of an "omeid" - one who stands fixed in his completeness. The praise that "he did not change" reflects this constancy, and through the avodah of kindling the menorah ("Beha'alosecha" - raising up), Aharon himself was continually elevated.