Exodus 24:3–4
3 Moses came and told the people all the words of the Lord and xall the rules.1 And all the people answered with one voice and said, y“All the words that the Lord has spoken we will do.” 4 And zMoses wrote down all the words of the Lord. He rose early in the morning and built an altar at the foot of the mountain, and twelve apillars, according to the twelve tribes of Israel.
Exodus 31:18
18 And he gave to Moses, when he had finished speaking with him on Mount Sinai, the ttwo tablets of the testimony, tablets of stone, written with uthe finger of God.