Exodus 24:7-8

7Then he took the Book of God's Covenant and he read it to the people. They replied, ‘We will do everything that the Lord has told us. We will obey his commands.’

8Then Moses used the blood in the bowls to splash on the people. He said, ‘This blood shows that you accept the covenant that the Lord has made with you. You agree to obey the rules of his covenant.’