All of creation waited in anticipation for Man to arrive. When Man makes proper use of the world, all of the world has meaning.
When in the course of time Man misused the world and didn’t live up to his calling, the unfulfilled earth waited in anticipation for Israel to receive the Torah and begin the process of bringing all of Mankind back to its mission and calling as אדם.
Therefore, the Midrash teaches us, God made a condition with the earth that if Israel accepts the Torah, all is good, but if not, the earth should revert to confusion. It is through Israel that the world receives the Torah. It is through the Torah’s message that Mankind and the earth find their true purpose. (The sixth refers to the 6th day of Sivan when the Torah was given)
The sixth also teaches us to extend part of the sixth day of the week into Shabbos. The sixth day of creation, the day that concludes all of creation, with Man’s mission, gives meaning to the previous days. Shabbos is a continuation and constant reminder of this sixth day message.
Beraishis 1:31, Pages 39-40
