Bartholomew: After all, the commandment was Thou shalt not kill. It seems pretty clear to me.
It's not as clear as it seems to you. When you go to the Bible gateway and enter your phrase you will be surprised that in most translations you do not find it at all, even not in the modernised version 'you shall not kill'. Nearly all modern translations are much closer to the original by translating 'You shall not murder'.
That's a difference.