Exodus 30:7

And Aharon shall burn sweet incense upon it from morning to morning: when he ordereth the lamps, be shall burn it.

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].

והקטיר עליו אהרן קטורת, “and Aaron shall burn on it the incense;” the word “Aaron” cannot be understood literally, as he would not live forever. Even during his lifetime, his sons, i.e. ordinary priests, were permitted to offer incense on this altar. The reason he has been mentioned by name is that according to the Talmud in tractate Yuma, folio 26, whenever the High Priest demanded to offer the incense he took precedence over ordinary priests. The Talmud there describes the procedure used to determine which priest would be chosen each day for that task. One of the most important factors in choosing such a priest was if he had never had the opportunity to perform that duty he was given preference over his colleagues. There was a tradition according to which priests who had performed this duty would become wealthy. Normally, lots were drawn between the priests on duty on that particular day. Lighting the menorah, also described as being performed by Aaron in Exodus 27,21, was also permitted to be performed by ordinary priests, seeing that both Aaron and his sons are mentioned in that context.