The written Torah is considered "awakening from Above" and the oral Torah is an awakening from below. And together they are called, "six years he shall serve; and in the seventh he shall go out free."
This is so because the essence of the work is specifically where there is resistance. And it is called Alma (Aramaic: world) from the word He’elem (concealment). Then, when there is concealment, there is resistance, and then there is room for work. This is the meaning of the words of our sages, "Six thousand years the world, and one ruined." This means that the concealment will be ruined and there will be no more work. Rather, the Creator makes him wings, which are covers, so he would have work.