Exodus 24:3; Exodus 24:4

3 Then Moses came and recounted 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!"

4 Moses wrote down all the words of the LORD . Then he arose early in the morning, and built an altar at the foot of the mountain with twelve pillars for the twelve tribes of Israel.