2And he shall lay his hand on the head of his offering and kill it at the entrance of the tent of meeting, and Aaron’s sons the priests shall throw the blood against the sides of the altar.
The Lord stipulated that the priests were to gather the blood and throw it against the altar. It was not to be used for any other purpose. See commentary on Leviticus 1:4.
2 And he shall lay his hand on the head of his offering and kill it at the entrance of the tent of meeting, and Aaron’s sons the priests shall throw the blood against the sides of the altar.