The Torah in Parashat Ki-Tisa (32:15) tells that the stone tablets which Moshe brought down from Mount Sinai were engraved with God’s commands by God Himself, and the text appeared on both sides of the stones. Rashi, based on the Gemara (Shabbat 104a), comments that this marked a miraculous quality of the tablets.
Rav Moshe Greenwald, in his Arugat Ha’bosem (Parashat Balak), elaborates on the nature and significance of this aspect of the tablets. The Ten Commandments were divided into two groups of five, with the first five commandments engraved on the right tablet, and the last five on the second tablet. If the commandments were written on both sides of the tablets, then it turns out that each stone actually contained all Ten Commandments – five on either side. Since the first five are written on the right stone and the next five on the left, each stone had the first five on one side and the next five on the other. This was done, Rav Greenwald suggests, to emphasize the interconnectedness of the two basic groups of mitzvot – our responsibilities to God, which are encapsulated in the five commandments, and our obligations to each other, which are reflected in the last five commandments. If each stone contained just one of the two sets of commandments, this may have given the impression that these two basic areas of responsibility can exist independent of one another. The fact that each stone contained all Ten Commandments underscores the point that our religious observance is fundamentally incomplete if we commit only to one area and not to the other.
The Gemara in Masekhet Megilla (15a) writes that when Ester sent her servant to Mordechai to ask why he sat in mourning (“la-da’at ma zeh ve-al ma zeh” – Ester 4:5), she was actually inquiring as to whether the Jews had perhaps transgressed the Torah: “Perhaps Israel had transgressed the five books of the Torah, about which it is written, ‘mi-zeh u-mi’zeh heim ketuvim’ (‘they were written on one side and on the other’).” Significantly, Chazal associate Ester’s concern for the Jews’ spiritual condition with this particular quality of the tablets – that the text was engraved on both sides. The idea, perhaps, is that when we embark upon the process of cheshbon ha-nefesh (introspection), when we examine our current state to identify the areas that require improvement, we need to reflect upon the inseparable connection between the two sets of commandments. We cannot focus on just one or the other, examining either our devotion to God or our interpersonal conduct. When trying to improve, we must bear in mind the fact that “mi-zeh u-mi’zeh heim ketuvim,” each stone contained all Ten Commandments, as all areas of Jewish life are deemed equally significant and demand equal focus and attention.
(Based on a devar Torah by Rabbi Dov Loketch)