Ramban, on Exod 30:7

AND AARON SHALL BURN THEREON INCENSE. This commandment [of burning the incense] did not devolve upon the High Priest alone, but was also incumbent upon the common priests, as is the law of the lighting of the lamps mentioned right beside it, [every morning, when he dresseth the lamps], although of that too it says, And when Aaron lighteth the lamps, and yet it does not apply to the High Priest alone, as He said above, Aaron and his sons shall set in order. Therefore I do not know why He mentioned Aaron in both of them, and did not say “the priest” [which would signify any — even a common-priest]. Perhaps it is because of Scripture’s statement further, And Aaron shall make atonement upon the horns of it once in the year, which was done by Aaron only, [because the reference there is to the Service on the Day of Atonement which could be performed only by the High Priest — therefore He also mentioned the name of Aaron in the verse before us and in the following verse]. Or it may be that He hinted that it was to be Aaron who [at the first time] was to begin the burning of the incense and the lighting of the lamps. Similarly at the end of Seder Emor el hakohanim He said, Aaron shall set in order, and He did not mention his sons, because it was Aaron who performed it first. The phrase a statute forever mentioned there, refers to the commandment [of kindling the lamps, and does not mean that it is a statute forever that only the High Priest do it].