Exodus 24:3-8

3
When Moses went and told the people all the LORD’s words and laws, they responded with one voice, “Everything the LORD has said we will do.”

4
Moses then wrote down everything the LORD had said.
He got up early the next morning and built an altar at the foot of the mountain and set up twelve stone pillars representing the twelve tribes of Israel.

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

6
Moses took half of the blood and put it in bowls, and the other half he splashed against the altar.

7
Then he took the Book of the Covenant and read it to the people. They responded, “We will do everything the LORD has said; we will obey.”

8
Moses then took the blood, sprinkled it on the people and said, “This is the blood of the covenant that the LORD has made with you in accordance with all these words.”

- biblegateway.com