Exodus 24:6-8

Moses drained half the blood from these animals into basins. The other half he splattered against the altar. Then he took the Book of the Covenant and read it aloud to the people. Again they all responded, “We will do everything the LORD has commanded. We will obey.” Then Moses took the blood from the basins and splattered it over the people, declaring, “Look, this blood confirms the covenant the LORD has made with you in giving you these instructions.”