So Moses took some of the anointing oil and some of the blood which was on the altar and sprinkled it on Aaron, on his garments, on his sons, and on the garments of his sons with him; and he consecrated Aaron, his garments, and his sons, and the garments of his sons with him.
Blood and oil. The body and garments of the priests were sprinkled with them. As I read this, the practical and the metaphorical both came to mind.
The practical is this: these clothes were going to be spattered with blood and oil on a daily basis. The sacrifices called for the priests to be handling oil in all the grain offerings and blood in every sacrifice that involved an animal dying. These clothes, lovely though they may have been on the day they were first placed on Aaron, would come to be spotted with the oil and blood of continual sacrifice.
The metaphorical is this: blood (as will be said in Leviticus 17) contains the life of a creature and oil is symbolic of the Holy Spirit. The metaphor; the symbol being that the priest (and every believer, by dint of what is said in Revelation 5) should be covered in life and the Holy Spirit. Jesus told His disciples that He came to give life and that more abundantly. Jesus said He would send the Comforter, the Holy Spirit, and He has.
The application is closely tied to the symbolic in this passage: believers (that would be me) should be marked by the life of our sacrifice (Jesus) and the anointing oil (the Holy Spirit). A side note that occurred to me as I was writing is that the believer should be marked by every sacrifice. I should be living in such a way that the sacrifices I make are obvious to others; not because I proclaim them, but because they leave marks on me that can easily be seen whether I announce them or not. My life should be marked by the death of Jesus, the anointing of the Holy Spirit, and my own sacrifices made in obedience to God.