The priest was not required to enter into the holy place in order to sprinkle the blood on the curtain or the altar of incense. This indicates that no defilement had taken place in the sanctuary, and thus there is no need for blood there. All activity takes place at the altar of burnt offering in the courtyard of the tabernacle.
25 Then the priest shall take some of the blood of the sin offering with his finger and put it on the horns of the altar of burnt offering and pour out the rest of its blood at the base of the altar of burnt offering.