Ramban (Nachmanides) on the Torah

Scripture states here, and thou shalt command [and does not say, “command the children of Israel”], because He always said with reference to the Tabernacle and thou shalt make, which means by your command [i.e., “you Moses command them to do it”]. Therefore He said here “and you yourself command them that they bring to you the oil for the light.” [It says that they bring and not “that they make”] because they had no way of making the oil in the wilderness; [therefore they were told] to bring it if they had it in reserve. Actually it were the princes that brought it.
The meaning of the word eilecha (unto thee) — [that they bring ‘unto thee’ pure olive oil] is that they were to bring it to Moses and he would see if it was pure and beaten properly. A similar intent is present in the verse, Command the children of Israel, that they bring unto thee [pure olive oil beaten for the light].
The meaning of the expression of the children of Israel, is that they bring you the oil from the children of Israel, from whoever has it in his possession, just as He said, of every man whose heart maketh him willing. Similarly He said, And bring thou near unto thee Aaron thy brother, and his sons with him, meaning that you yourself are to call them and give them the tidings of this distinction. And thou shalt make them holy garments, Verse 2. means by commanding the wise men who wrought the work as was done with all the work of this pattern. Likewise, And thou shalt speak unto all that are wise-hearted means that Moses himself is to speak to them, for he will recognize their qualifications and know which is the work that ought to be given over to each of them. Now because He said, And bring thou near; And thou shalt make,, Verse 2. it was necessary that He explain, And thou shalt speak unto all that are wise-hearted […that they make Aaron’s garments], for it was by the command of Moses that they were to make the garments,] means that Moses himself is to speak to Aaron and his sons, as explained above, Verse 2 following [And thou shalt make holy garments for Aaron…] also means that Moses himself is to make them; hence it was necessary to explain in Verse 3 [And thou shalt speak unto all that are wise-hearted… that they make Aaron’s garments], meaning that they are to be made in the same way as the rest of the work. as was the case with the rest of the work of which it is said, See, I have called by name Bezalel etc.
TO CAUSE A LAMP TO BURN ‘TAMID’ (CONTINUALLY). “Doing something each and every night is called tamid (continually), just as you say, olath tamid (a continual burnt-offering) and yet it was brought only from day to day. Similarly in the case of the meal-offering made on the griddle [brought every day by the High Priest] it is said tamid, and yet it was brought only half of it in the morning, and half thereof in the evening. However, the word tamid used in connection with the showbread signifies [the whole period without interruption] from Sabbath to Sabbath.” Thus is Rashi’s language. But the Midrash [interpretation] of our Rabbis is not so. Instead they taught in the Sifre as follows:.— For meaning of “Sifre” see Seder Yithro, Note 52. “The seven lamps shall give light. I might think that they are to burn always; Scripture therefore says, from evening to morning. I might then think that they are to burn from evening to morning and then he is to extinguish them; Scripture therefore says, the seven lamps shall give light. — How is this to be understood? The seven lamps shall give light from evening to morning. Before the Eternal continually — this refers to the neir ma’aravi, and therefore is to burn continually, for it is to that particular light that the expression before the Eternal continually, applies. See further Note 23 as to which of the seven lamps in the candelabrum the term neir hama’aravi has reference to. which is to burn perpetually, since the candelabrum was lit from it in the evening.” In the Torath Kohanim 13:7. — Torath Kohanim is another name for the Sifra, which is the Halachic Midrash of the Tannaim on the Book of Leviticus. the Rabbis have likewise said: “To cause a lamp to burn continually — this means that ‘the western light’ should burn perpetually.” They have further taught there: “If [the priest who came into the Sanctuary in the morning to trim the candelabrum] found that it had gone out, he cleaned it out and kindled it from [the fire upon] the altar of the whole-offering.” Thus it is clear that even at daytime he kindled the neir ma’aravi, for that lamp always burnt regularly [and not as Rashi has it that the candelabrum was lit only in the evening]. And in Tractate Tamid we have been taught as follows: “[The priest] who was privileged to clean out the candelabrum [during the morning service] entered [the Sanctuary], and if he found the two easternmost lamps burning, he cleaned out the rest [leaving them to be lit during the evening service], but the two easternmost lamps he left burning as they were. If he found that [the two easternmost lamps] had gone out, he cleaned them out and kindled them from those that were still burning, and then cleaned out the rest” [leaving them to be kindled during the evening service]. was then kindled from the fire upon the altar of the burnt-offering which stood outside in the Sanctuary Court. Now this anonymous Mishnah conforms to the opinion of Rabbi Note 64. who says that the lamps of the candelabrum were placed in an east-west direction, and the neir ma’aravi (the western light) in his opinion is the second light from the east side., since that expression implies that there is one light still further away from the Holy of Holies [where the Divine Glory abided]. Hence the first lamp of which it might be said that it is before the Eternal is the second from the east, and since we must not pass over an occasion for performing a religious act, the second light from the east becomes affixed as being before the Eternal, and that is the neir ma’aravi (the western light). — There is, however, another opinion [mentioned further on in the text] that the candelabrum was placed in a south-north direction, and the term neir ma’aravi was given to the middle lamp, because the three lamps on each side turned towards the center one. — Menachoth 98b. See also Shabbath 22 b, Rashi. It is called ma’aravi (western) because it is to the west of the first, and since he has to kindle the western light to fulfill therewith the Divine command before the Eternal continually, he must kindle also the easternmost lamp, for the second lamp cannot be called “western” until there be an “eastern” next to it. But according to the opinion of the Sage who says that the candelabrum was placed in a north-south direction, the neir ma’aravi was the middle one — on the central shaft of the candelabrum — and that light alone he kindled in the morning [for since none of the lamps were “outside” of it towards the east it was not necessary that another lamp be lighted]. Thus the principle is clear that the expression before the Eternal continually applies to “the western light,” which burns regularly day and night.