Well, it's kind of hard to come up with an original domain name that hasn't already been taken. So, wanting to use 'Sabbath' in the the name somehow. A decision was made to use numbers with meanings relating to the Sabbath as follows:
[Four] = The Fourth Commandment: Remember the Sabbath and keep it holy.
[Seven] = Creation's Last day, the day of rest. The Seventh day (Saturday) when God, Jesus, the 'Word' rested from all His work He had done.