Exodus 24:4-8

4Moses wrote down all the words of the Lord. Then he got up early in the morning, and built an altar [for worship] at the foot of the mountain with twelve pillars (memorial stones) representing the twelve tribes of Israel.

5Then he sent young Israelite men, and they offered burnt offerings and sacrificed young bulls as peace offerings to the Lord.

6Moses took half of the blood and put it in large basins, and [the other] half of the blood he sprinkled on the altar.

7Then he took the Book of the Covenant and read it aloud to the people; and they said, “Everything that the Lord has said we will do, and we will be obedient.”

8So Moses took the blood [which had been placed in the large basins] and sprinkled it on the people, and said, “Behold the blood of the covenant, which the Lord has made with you in accordance with all these words.”