מִחוּץ֩ לְפָרֹ֨כֶת הָעֵדֻ֜ת בְּאֹ֣הֶל מוֹעֵ֗ד יַעֲרֹךְ֩ אֹת֨וֹ אַהֲרֹ֜ן מֵעֶ֧רֶב עַד־בֹּ֛קֶר לִפְנֵ֥י יְהוָ֖ה תָּמִ֑יד חֻקַּ֥ת עוֹלָ֖ם לְדֹרֹֽתֵיכֶֽם׃
Zewnątrz zasłony (arki) świadectwa, w przybytku zboru, ustawiać je będzie Ahron od wieczora aż do rana przed obliczem Wiekuistego ustawicznie: ustawa to wieczna w potomstwie waszém.
Tosafot
And does He require its light? Didn’t all those forty years: It is a wonder: Why did it mention forty years? The whole world always walks by the light of the Omnipresent! And some explain it as, "Did Aharon need its light when he went inside?" [Accordingly,] didn't the pillar of cloud give light to them in all the places those forty years? It is as we say in the Baraita of the Work of the Tabernacle, "He would look inside a pitcher and know what is inside it; in a barrel and know what is inside it." And it so implied in Torat Kohanim - that it is referring to the priests. As there, it teaches the version, "And did they need the lamp? And didn't all of those forty years they not require the lamp? As it is stated (Exodus 40:38), 'For the cloud of the Lord was over the tabernacle.'" However at the end of [the chapter entitled] Kol Korbanot (Menachot 26b), it is implied that it is referring to the Divine Presence. As it cites it regarding that which Rabbi Elazar said, "I do not require [it] for eating and I do not require it for its light." And there it also said, "'To the curtain of the testimony' (Leviticus 24:3) - it is testimony to all who come to the world that the Divine Presence rests among Israel. But perhaps you will say (ask), 'Do I require its light,' Didn't all those forty years [etc.]?"
Or HaChaim
It is also possible that the laws pertaining to the Candlestick were written adjoining the legislation about the festival of Tabernacles to teach us some lessons about the difference between physical and spiritual light. G'd neither needs the light of the Candlestick to illuminate the Tabernacle for Him, nor did the Jewish people travel through the desert for 40 years using physical light (compare Torat Kohanim on the words מחוץ לפרוכת in verse 3). The ענני הכבוד, the clouds of glory i.e. the שכינה, illuminated the way for the Jewish people and the shade they provided actually screened out the sunlight during all those years (compare Tossaphot on Shabbat. 22,B). It follows that the commandment to light the Candlestick daily was only for the sake of the dividing curtain which was so called as it provided testimony for the nations of the world that G'd's presence resided within the camp of the Jewish people.
Ramban
AND AARON DID SO. The meaning thereof is to state that it was Aaron who lighted the lamps all his life. For although the commandment may be validly performed by his sons, as it is said, Aaron and his sons shall set it in order,26Exodus 27:21. it was he who was zealous in the fulfillment of this great commandment which alludes to an exalted matter and sublime secret.27See my Hebrew commentary p. 222. Perhaps he deduced an allusion to this [i.e., that during his lifetime it was he who was to light the lamps] from the verse, Without the Veil of the Testimony, in the Tent of Meeting, shall Aaron set it in order from evening to morning,28Leviticus 24:3. [implying] that it was him whom G-d chose [to light the lamps] as long as he lived. And it is for this reason that now too, He said, Speak unto Aaron … When thou lightest,29Verse 2. and He did not say “Speak unto Aaron and his sons … When ye light [the lamps].”