Exodus 24:4-6

New Century Version

⁴ So Moses wrote down all the words of the Lord. And he got up early the next morning and built an altar near the bottom of the mountain. He set up twelve stones, one stone for each of the twelve tribes of Israel. ⁵ Then Moses sent young Israelite men to offer whole burnt offerings and to sacrifice young bulls as fellowship offerings to the Lord. ⁶ Moses put half of the blood of these animals in bowls, and he sprinkled the other half of the blood on the altar.