Exodus 24:7-8

Then 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.” So 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.” [1 Cor 11:25; Heb 8:6; 10:28, 29]