Exodus 32:16

32:16 Now the tablets were the work of God, and the writing was the writing of God, engraved on the tablets.

Exodus 31:18

31:18 He gave Moses two tablets of testimony when he had finished speaking with him on Mount Sinai, tablets of stone written by the finger of God. ¹ 

Exodus 32:15

32:15 Moses turned and went down from the mountain with ²  the two tablets of the testimony in his hands. The tablets were written on both sides – they were written on the front and on the back.

[31:18]  ¹ sn The expression “the finger of God” has come up before in the book, in the plagues (Exod 8:15) to express that it was a demonstration of the power and authority of God. So here too the commandments given to Moses on stone tablets came from God. It too is a bold anthropomorphism; to attribute such a material action to Yahweh would have been thought provoking to say the least. But by using “God” and by stating it in an obviously figurative way, balance is maintained. Since no one writes with one finger, the expression simply says that the Law came directly from God.

[32:15]  ¹ tn The disjunctive vav (ו) serves here as a circumstantial clause indicator.