Exodus 24:5-6, 8

And he sent young men of the people of Israel, who offered burnt offerings and sacrificed peace offerings of oxen to the LORD. And Moses took half of the blood and put it in basins, and half of the blood he threw against the altar.

And Moses took the blood and threw it on the people and said, “Behold the blood of the covenant that the LORD has made with you in accordance with all these words.”