@village
i can see how it appears that way, but it's not a punishment for blaspheme. The statement made is that anyone who sins defiantly has blasphemed. The NASB makes this much clearer by making it, "but the person who does anything defiantly..." So it was considered blaspheme against God to flagarantly disregard gods law, like this man did.
i was hoping you'd ask about why they were ignorant as to what to do. So, technically - where the rule was to be, "cut off from his people" was not a death sentence. At this point I know what you're thinking probably, but bear with me.
In the book Daily Life in the Times of Jesus, Henri Daniel-Rops makes reference to this phrase and explains that it meant banishment and not death. When the Israelites settled they had cities to which these banished people were sent to live.
However, they weren't settled in the promised land here, they were in the wilderness. If they banished this man he would effectively die. So they didn't know what to do with him and remanded him into custody, after which God intervened and gave a verdict himself.
As to the Ten Commandments, I'll check out what you're referring to and reply in a PM so as to stay on topic.