Exodus 24:3-8

³Moses came and told the people all the words of the LORD and all the ordinances; and all the people answered with one voice, and said, "All the words which the LORD has spoken we will do." ⁴And Moses wrote all the words of the LORD. And he rose early in the morning, and built an altar at the foot of the mountain, and twelve pillars, according to the twelve tribes of Israel. ⁵And he sent young men of the people of Israel, who offered burnt offerings and sacrificed peace offerings of oxen to the LORD. ⁶And Moses took half of the blood and put it in basins, and half of the blood he threw against the altar. ⁷Then he took the book of the covenant, and read it in the hearing of the people; and they said, "All that the LORD has spoken we will do, and we will be obedient." ⁸And Moses took the blood and threw it upon the people, and said, "Behold the blood of the covenant which the LORD has made with you in accordance with all these words."