Leviticus 8:11

And he sprinkled upon the altar seven times, and sanctified the altar and all its vessels, and the laver and its foundation to sanctify them.

AND HE SPRINKLED THEREOF [i.e., of the anointing oil] UPON THE ALTAR. Rashi commented: “I do not know where Moses was commanded about these sprinklings.” It is possible that that which He said of the altar, and thou shalt sanctify the altar, and the altar shall be most holy,, Verse 10. means that he should add this sanctification to the altar through the sprinklings [of the anointing oil], and it could not be done merely by anointing the altar, for the expression and the altar shall be most holy, means that he should give it an additional sanctity above that of the other anointed things in the Tabernacle and all its vessels. Moses thus sanctified the altar in the same way that he was commanded to do to the ministering priests, concerning whom He said, and thou shalt sprinkle it upon Aaron, and upon his garments,, 29:21. since the altar, which is the vessel for the offerings, is not of a lesser degree of holiness than the garments of the ministering priests, and it is an inference from minor to major [that if the garments had to be sprinkled with the anointing oil, surely the altar, being more holy, had to be sprinkled]! And so also is it said with reference to the Day of Atonement, And he shall sprinkle of the blood upon it [the altar] with his finger seven times, and cleanse it, and hallow it from the uncleannesses of the children of Israel. Thus [we see that] all sanctifications of the altar were done by sprinklings, and it follows all the more so that [when the altar was consecrated] at the very beginning that it had to be sanctified by sprinkling from uncleanness and “strangeness” [i.e., from that which is not holy].
Scripture did not mention here [in Verse 13] the anointing of Aaron’s sons, for it is self-evident that Moses did to them as he did to their father, in accordance with that which he was commanded, And thou shalt anoint them, as thou didst anoint their father, and He included it here in saying with reference to the sons that everything was done as the Eternal commanded Moses.
It appears to me that the anointing of Aaron’s sons was not done by means of pouring the oil on their heads, for that is said only of Aaron, Then shalt thou take the anointing oil, and pour it upon his [Aaron’s] head, and anoint him, but the anointing of the sons is not mentioned there at all, as it was not done by means of pouring the oil as in Aaron’s case. It is [also] possible that there was no anointing of the sons, except for the sprinklings which Moses sprinkled on Aaron’s sons and their garments from the oil of anointment. Thus you see in the section of And this is the thing that thou shalt do unto them to hallow them, Verse 1. that He commanded to anoint the father [i.e., Aaron], as it says, Then shalt thou take the anointing oil, and pour it upon his head, but did not command to anoint the sons at all, either by pouring of the oil, or by anointing. However, in the section of the erection of the Tabernacle He says, And thou shalt anoint them, as thou didst anoint their father, because He did not mention the sprinklings there at all, [hence He mentioned “anointing,” whilst referring really to sprinkling]. Similarly, in the section of the oil of anointment [the verse mentions anointing of Aaron and his sons because it does not mention the sprinklings at all]. But both sprinkling and anointing are nowhere mentioned with reference to the sons of Aaron in one place. Therefore I say that he only did one of the two to them, namely, the sprinklings.