Six days shall work be done, but on the seventh
During the forty years that the Israelites wandered in the desert they carried with them a portable temple referred to as the Tabernacle or the Mishkan. The creative acts that are forbidden on Shabbat are those acts similar to the skills that went into building or assembling the Mishkan. The Talmud outlines 39 different categories of such creative acts that are forbidden to do on Shabbat. They represent our ultimate power of creativity which is to build a temple that accommodates the presence of G-d on earth. Of course we know that G-d does not literally dwell in the Mishkan, however, the Mishkan symbolizes the greatest accomplishment of a human being which is to serve to make manifest G-d, the presence of Absolute Good.
Why then are we commanded to refrain on Shabbat from the greatest act of human creativity and accomplishment? To ensure that we are truly doing it for G-d’s sake to bring good to the world. Otherwise it could be just an ego trip.
Imagine it is Friday afternoon, it’s the dawn of the sixth millennium, six thousand years we have been waiting for the Messiah and finally he has come and we are building the tabernacle. Within minutes we complete the ultimate accomplishment we have been dreaming of, but Shabbat is coming soon. We need just ten more minutes to complete the temple and infuse this world with the complete presence of G-d — but Shabbat is starting in five minutes. Would we stop? Could we stop? Are we willing to let go of the greatest service to G-d, the ultimate accomplishment humanly possible? Are we going to blow the rectification of the universe for five minutes of Shabbat and wait 25 hours to resume?
But this is exactly the message of Shabbat and the blessing it bears.
If we are really building the Temple for G-d than if the Boss says stop we stop. If you cannot stop then you were building the temple for yourself.
Shabbat is a time to stop. And when we stop on Shabbat that retroactively affirms that everything we have done until now is not about our ego but truly in service of bringing the greater good to the world.