Exodus 24:5-7

Young's Literal Translation

⁵ and he sendeth the youths of the sons of Israel, and they cause burnt-offerings to ascend, and sacrifice sacrifices of peace-offerings to Jehovah -- calves.

⁶ And Moses taketh half of the blood, and putteth in basins, and half of the blood hath he sprinkled on the altar;

⁷ and he taketh the Book of the Covenant, and proclaimeth in the ears of the people, and they say, `All that which Jehovah hath spoken we do, and obey.'