At the end of 40 days and 40 nights, G-d gave me the two
stone tablets, the Tablets of the Covenant.
Deuteronomy 9:11
The first five commandments were chiseled into the first tablet, and the second five commandments were chiseled into the second tablet. Since there were many more letters in the first five commandments than in the second five, it follows that there were many more letters on the first tablet than there were on the second tablet.
Furthermore, the size of the letters and the space between the letters and lines was the same in both. Nonetheless, the two tablets were miraculously the same size.
Moreover, the letters were engraved straight through the tablets, from one side to the other, yet the words could be read regularly from both sides.
This is why Scripture emphasizes that the tablets were made of stone. The miraculous way that they were written was manifest in the lowest level of physical existence, solid rock. This teaches us that the purpose of the sublime spirituality inherent in the Torah is that it permeate all of physical reality, down to its lowest, most material level.
— Daily Wisdom 3