'Horns of the Altar' in the Bible

Take some of the bull’s blood and apply it to the horns of the altar with your finger; then pour out all the rest of the blood at the base of the altar.

“Once a year Aaron is to perform the purification rite on the horns of the altar. Throughout your generations he is to perform the purification rite for it once a year, with the blood of the sin offering for atonement. The altar is especially holy to the Lord.”