Exodus 24:4-8

4And Moses wrote all the words of Jehovah, and rose up early in the morning, and builded an altar under the mount, and twelve pillars, according to the twelve tribes of Israel. 5And he sent young men of the children of Israel, who offered burnt-offerings, and sacrificed peace-offerings of oxen unto Jehovah. 6And Moses took half of the blood, and put it in basins; and half of the blood he sprinkled on the altar. 7And 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. 8And 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.