Read: Leviticus 4
Then the priest is to take some of the blood with his finger and put it on the horns of the altar of burnt offering and pour out the rest of the blood at the base of the altar. Lev 4:30
In the book of Leviticus, the five great offerings specified there set forth for us so clearly and helpfully the basic needs of our humanity, needs which God has built into every one of us, and how these needs can be met — the only way in which they can be met. Here we come to the fourth of these offerings, the sin offering.
Remember that in the previous offerings, just as in the sin offering, blood had to be shed, and a death had to occur. But all the blood of the animal was poured out at the foot of the altar. But with the blood of the sin offering something unusual was always done. The blood had to be sprinkled seven times before the LORD. Then, in the case of the offering for the anointed priest as we see here, it had to be put on the horns of the altar of incense which stood in the holy place, right in front of the veil which guarded the holy of holies — i.e., right before the presence of the LORD.