Christians - can you tell me what the Tenth Commandment is?

Great question. You are uming, in error that the admonissions given to Moses were the same commandments that were already on the tablets. Reread the Chapters in their entirety and see that it says that the same words were on the second set of tablets as the first. Yes, God rehashes some instructions to Moses but they are not the Ten Commandments as you suppose. Remember, there are thousands of these misconceptions and they have all been answered.