Exodus 32:15, 16, 19

Moses turned and went down the mountain with the two tablets of the covenant law in his hands. They were inscribed on both sides, front and back.

The tablets were the work of God; the writing was the writing of God, engraved on the tablets.

When Moses approached the camp and saw the calf and the dancing, his anger burned and he threw the tablets out of his hands, breaking them to pieces at the foot of the mountain.