Exodus 24:5-8

And he sent young men of the children of Israel, who offered burnt-offerings, and sacrificed peace-offerings of oxen unto Jehovah. And Moses took half of the blood, and put it in basins; and half of the blood he sprinkled on the altar. And he took the book of the covenant, and read in the audience of the people: and they said, All that Jehovah hath spoken will we do, and be obedient. And Moses took the blood, and sprinkled it on the people, and said, Behold the blood of the covenant, which Jehovah hath made with you concerning all these words.