Exodus 24:1-5

Then He said to Moses, “Come up to the Lord, you and Aaron, Nadab and Abihu, and seventy of the elders of Israel, and you shall worship at a distance.

Moses alone, however, shall approach the Lord, but they shall not approach, nor shall the people come up with him.”

Then Moses came and reported to the people all the words of the Lord and all the ordinances; and all the people answered with one voice and said, “All the words which the Lord has spoken we will do!”

And Moses wrote down all the words of the Lord. Then he got up early in the morning, and built an altar at the foot of the mountain with twelve memorial stones for the twelve tribes of Israel.

And he sent young men of the sons of Israel, and they offered burnt offerings and sacrificed bulls as peace offerings to the Lord.