Exodus 24:4-6

Young's Literal Translation

⁴ And Moses writeth all the words of Jehovah, and riseth early in the morning, and buildeth an altar under the hill, and twelve standing pillars for the twelve tribes of Israel;

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;