Eleazar to Apply the Blood of the Red Heifer by Sprinkling Towards the Front of the Tent of Meeting Seven Times (Numbers 19:4).
“ And Eleazar the priest shall take of her blood with his finger, and sprinkle her blood towards the front of the tent of meeting seven times.”
Eleazar the priest, Aaron's eldest son, was to be present, deputising for the High Priest who could not come into contact with a ceremonial which spoke of death. The slaughter was not specifically an offering, for it was not offered on the altar (although it was a purification for sin offering - verses 9. 17), but Eleazar's next action was to take some of the blood from the red heifer on to his finger and sprinkle it towards the front of the Tent of meeting seven times (compare Leviticus 16:14-19). The idea was to apply the blood before Yahweh even though outside the camp. This was done seven times in order to signify the divine completeness of the atonement.
This may be compared with the original sacrifice of the Passover lamb. That too was not on an altar. But it was also stated to be a sacrifice ((Exodus 12:27).