What does Genesis 2:6 mean?

The previous verse described the earth as lacking cultivated crops. At that point, there was no one to work the ground and no rain. This verse tells us how the garden got its water with no rain: mists or streams came up from the ground. The impression is of underground streams, the so-called "fresh water ocean," which would saturate the land, perhaps on a cyclical basis. This fits the description of upcoming verses of the rivers that water the Garden of Eden and the region around it. It also fits with the farming practices of the Mesopotamian region that relied on cyclical flooding to sustain crops.

As we saw in chapter 1, God had prepared a world in which humans could grow and gather food before He even made man. Likewise, He had made a world in which humans were needed to care for all He had made and help to bring order to it.