The tablets were the work of God, and the writing was the writing of God, engraved on the tablets.
Here is, I. The favour of God to Moses, in trusting him with the two tables of the testimony, which, though of common stone, were far more valuable than all the precious stones that adorned the breast-plate of Aaron. The topaz of Ethiopia could not equal them, Exo 32:15, Exo 32:16.
Commenting on Exodus 32:15-20
And when Joshua heard the noise of the people, as they shouted,.... Dancing about the calf: when Moses went up into the mount, Joshua went with him, and tarried in a lower part of the mount all the forty days until he returned, see Exo 24:13 though not so low as the bottom of the mount where the people were, nor so near it as...
And the tables [were] the work of God, and the writing [was] the writing of God, graven upon the tables. (h) All these repetitions show how excellent a thing they defrauded themselves of by their idolatry.