God sent Adam forth from the Garden to till the soil from which he had been taken, work that requires sorting out, sowing, plowing, and harvesting.
In order to be able to live from the earth, man has to keep digging, weeding, and drawing forth from the ground.
The point is that the work of weeding out the harmful and proliferating the good can be done only in and with earth itself.
The war of man against thorns and thistles, insects and rodents, is an incessant struggle, and it is part of his work of Tikun, correcting the world.
However, the task of building, planting, and beautifying the earth is only part of the work of "Berur," of selection and cleansing.
Man also has the enormously difficult task of spiritual sorting out.
It is not enough to sow and harvest the fruits of the earth; man is also enjoined to give thanks, to say blessings from the heart.
Just as man eats of the products of his toil on the earth he has also to raise everything up to a higher level, restoring what he receives to its source.
This too is part of the process of sorting out.
–Rabbi Adin Steinsaltz
From In the Beginning, “The Tree of Knowledge,” p. 77 by Rabbi Adin Steinsaltz