Lighting the Holy Lights: B'Haalotcha Torah study - From the Torah to Hasidic Teachings

The Eternal One spoke to Moses, saying:

Speak to Aaron and say to him, “When you mount the lamps, let the seven lamps give light at the front of the lampstand.”Aaron did so; he mounted the lamps at the front of the lampstand, as the Eternal had commanded Moses.—Now this is how the lampstand was made: it was hammered work of gold, hammered from base to petal. According to the pattern that the Eternal had shown Moses, so was the lampstand made.

(2) WHEN YOU MOUNT THE LAMPS — Because the flame rises upwards (עולה), an expression denoting “ascending” is used of kindling them (the lights), implying that one must kindle them until the light ascends of itself (Sifra). — Furthermore our Rabbis derived from here (from the expression בהעלתך) that there was a step in front of the candelabrum upon which the priest stood while preparing the lights.

(3) AND AARON DID SO — This is stated in order to tell the praise of Aaron — that he did not deviate [from G-d's command] (cf. Siphre).

And the reason why it says AND AARON DID SO​ - to teach us that he was the one who lit the candles his whole life. And even though it can be done by anyone of his kids, as it says (Exodus 27:21) "it (the lights) shall be done by Aaron AND his kids" he was quick to do this amazing big Mitzva, which is signaling to higher place, and hidden mystery.

(3) ​As God has commended - ​ It has to be understood, why does the verse repeat itself by saying "as was commended" if it just said "and Aaron did so"? ... What it is telling us by saying "as it was commended" is the tale and praise of Aaron, that the reason why he did all of this (the entire priesthood) wasn't for the honor and praise he would get from the divine, but just to fulfill divine commend. As it is said (Psalms 40) "To do your will, O my God, I thrive."