Tosefta for Exodus 32:16

וְהַ֨לֻּחֹ֔ת מַעֲשֵׂ֥ה אֱלֹהִ֖ים הֵ֑מָּה וְהַמִּכְתָּ֗ב מִכְתַּ֤ב אֱלֹהִים֙ ה֔וּא חָר֖וּת עַל־הַלֻּחֹֽת׃

And the tables were the work of God, and the writing was the writing of God, graven upon the tables.

Tosefta Bava Kamma