On both their sides — Some on one table and some on the other, so that they were folded together like a book, to be deposited in the ark.
Related Commentaries of Exodus 32:15
Exodus 32:15
15 And Moses turned, and went down from the mount, and the two tables of the testimony were in his hand: the tables were written on both their sides; on the one side and on the other were they written.