The two versions of the 10 Commandments (one in Yitro and the 2nd in Va'etchanan) have different phrasing, most notably in commandments 4, 5 and 10.
What was actually written on the two tablets?
Some possibilities that I thought of (perhaps, others discussed some of these, too?):
- The Torah says regarding the luchot that they were written "on both sides". Could this mean that when viewing from one side it had the version from Yitro and the other side from *Va'etchanan?
- There were two sets of tablets. Could it be that the first one that G-d created had one version and the tablets that Moshe created had the 2nd version?
- Could this be a קרי / כתיב issue? I.e. one version was written but pronounced differently, and we are, for some reason reciting both versions because we're not completely sure what was written and what was "pronounced"?
There may be other ideas, of course.